User interface with toolbar for programming electrical stimulation therapy

ABSTRACT

The disclosure is directed to a user interface with a menu that facilitates stimulation therapy programming. The user interface displays a representation of the electrical leads implanted in the patient and at least one menu with icons that the user can use to adjust the stimulation therapy. The user may drag one or more field shapes from a field shape selection menu onto the desired location relative to the electrical leads. A manipulation tool menu may also allow the user to adjust the field shapes placed on the electrical leads, which represent the stimulation region. The programmer that includes the user interface then generates electrical stimulation parameter values for the stimulator to deliver stimulation according to the field shapes or field shape groups defined/located by the user. The field shapes may represent different types of stimulation representations, such as current density, activation functions, and neuron models.

This application claims the benefit of U.S. Provisional Application No.60/873,193, filed Dec. 6, 2006, the entire content of which isincorporated herein by reference.

TECHNICAL FIELD

The disclosure relates to electrical stimulation therapy, and moreparticularly, to programming electrical stimulation therapy.

BACKGROUND

Implantable electrical stimulators may be used to deliver electricalstimulation therapy to patients to treat a variety of symptoms orconditions such as chronic pain, tremor, Parkinson's disease, epilepsy,urinary or fecal incontinence, sexual dysfunction, obesity, orgastroparesis. In general, an implantable stimulator deliversneurostimulation therapy in the form of electrical pulses. Animplantable stimulator may deliver neurostimulation therapy via one ormore leads that include electrodes located proximate to target locationsassociated with the brain, the spinal cord, pelvic nerves, peripheralnerves, or the gastrointestinal tract of a patient. Hence, stimulationmay be used in different therapeutic applications, such as deep brainstimulation (DBS), spinal cord stimulation (SCS), pelvic stimulation,gastric stimulation, or peripheral nerve stimulation. Stimulation alsomay be used for muscle stimulation, e.g., functional electricalstimulation (FES), to promote muscle movement or prevent atrophy.

In general, a clinician selects values for a number of programmableparameters in order to define the electrical stimulation therapy to bedelivered by the implantable stimulator to a patient. For example, theclinician ordinarily selects a combination of the electrodes carried byone or more implantable leads, and assigns polarities to the selectedelectrodes. The selected combination of electrodes and their polaritiesmay collectively be referred to as an electrode configuration. Inaddition, the clinician selects an amplitude, which may be a current orvoltage amplitude, and, in the case of stimulation delivered the patientin the form of electrical pulses, a pulse width and a pulse rate. Agroup of parameters, such as a group including electrode combination,electrode polarity, amplitude, pulse width and pulse rate, may bereferred to as a program in the sense that they drive theneurostimulation therapy to be delivered to the patient. In someapplications, an implantable stimulator may deliver stimulation therapyaccording to multiple programs either simultaneously or on atime-interleaved, overlapping or non-overlapping, basis.

The process of selecting electrode combinations and other stimulationparameters can be time consuming, and may require a great deal of trialand error before a therapeutic program is discovered. The “best” programmay be a program that best balances greater clinical efficacy andminimal side effects experienced by the patient. In addition, someprograms may consume less power during therapy. The clinician typicallyneeds to test a large number of possible electrode combinations withinthe electrode set implanted in the patient in order to identify anoptimal combination of electrodes and associated polarities. Asmentioned previously, an electrode combination is a selected subset ofone or more electrodes located on one or more implantable leads coupledto an electrical stimulator. As a portion of the overall parameterselection process, the process of selecting electrodes and thepolarities of the electrodes can be particularly time-consuming andtedious.

The clinician may test electrode combinations by manually specifyingcombinations based on intuition or some idiosyncratic methodology. Theclinician may then record notes on the efficacy and side effects of eachcombination after delivery of stimulation via that combination. In somecases, efficacy and side effects can be observed immediately within theclinic. For example, spinal cord stimulation may produce paresthesia andside effects that can be observed by the clinician based on patientfeedback. In other cases, side effects and efficacy may not be apparentuntil a program has been applied for an extended period of time, as issometimes the case in deep brain stimulation. Upon receipt of patientfeedback and/or observation of symptoms by the clinician, the clinicianis able to compare and select from the tested electrode combinations.

In order to improve the efficacy of stimulation therapy, electricalstimulators have grown in capability and complexity. Modern stimulatorstend to have larger numbers of possible electrode combinations, largerparameter ranges, and the ability to simultaneously deliver multipleprograms by interleaving stimulation pulses according to differentprograms in time. Although these factors increase the clinician'sability to more finely adjust therapy for a particular patient ordisease state, the burden involved in optimizing the device parametershas similarly increased. Unfortunately, fixed reimbursement schedulesand scarce clinic time present challenges to effective programming ofstimulation therapy.

Existing lead sets include axial leads carrying ring electrodes disposedat different axial positions, and so-called “paddle” leads carryingplanar arrays of electrodes. Selection of electrode combinations withinan axial lead, a paddle lead, or among two or more different leadspresents a challenge to the clinician. The emergence of more complexelectrode array geometries presents still further challenges. The designof the user interface used to program the stimulator, in the form ofeither a physician programmer or patient programmer, has a great impacton the ability to efficiently define and select efficacious stimulationprograms.

SUMMARY

The disclosure is directed to a user interface with a toolbar, or menu,that facilitates stimulation therapy programming for a user. The userinterface may display a representation of the implanted electrical leadsin the patient in conjunction with at least one menu with icons that theuser can use to adjust the stimulation field of the stimulation therapywith one or more field shape groups. One menu may be a field shapeselection menu that provides field shapes to indicate the resultingstimulation field according to initial stimulation parameters. Anothermenu may be a manipulation tool menu that allows a user to performcertain actions on the field shapes to adjust the stimulation therapy.The user interface is designed to reduce the need for the user todirectly adjust stimulation parameters by focusing on the tissue andtherapy result.

The user may drag one or more field shapes or field shape groups fromthe field shape selection menu onto the desired location of theelectrical leads or elsewhere within the representation of thestimulation region. The manipulation tool menu may also allow the userto adjust the field shapes placed within the representation of thestimulation region, which represent the overall stimulation field withinthe representation of the stimulation region presented by the userinterface. The representation of the stimulation region may be mapped toimplanted electrodes, anatomy, or the like in an actual stimulationregion within the patient. The programmer that includes the userinterface then generates electrical stimulation parameters for animplantable stimulator to deliver stimulation therapy according to thefield shapes defined by the user and their position within therepresentation of the stimulation region. The field shapes may representdifferent types of stimulation fields, such as current density,activation functions, and neuron models.

In one example, the disclosure provides a method for presenting on adisplay at least one view of a representation of a stimulation regionand presenting on the display at least one field shape group within afield shape selection menu. The method also includes receiving inputselecting the at least one field shape group from the field shapeselection menu, receiving placement input placing the at least one fieldshape group at a position within the stimulation region, and generatingelectrical stimulation parameters based upon the field shape group andthe position within the representation of the stimulation region.

In another example, the disclosure provides a programmer having adisplay and a processor that presents on the display at least one viewof a representation of a stimulation region and at least one field shapegroup within a field shape selection menu. The programmer also includesa user interface that receives selection input selecting the at leastone field shape group from the field shape selection menu and placementinput placing the at least one field shape group at a position withinthe stimulation region, wherein the processor generates electricalstimulation parameters based upon the field shape group and the positionwithin the representation of stimulation region.

In an alternative example, the disclosure provides a computer readablemedium having instructions that cause a processor to present on adisplay at least one view of a representation of a stimulation regionand present on the display at least one field shape group within a fieldshape selection menu. The computer readable medium also has instructionsthat cause the processor to receive selection input selecting the atleast one field shape group from the field shape selection menu, receiveplacement input placing the at least one field shape group at a positionwithin the stimulation region, and generate electrical stimulationparameters based upon the field shape group and the position within therepresentation of the stimulation region.

The disclosure, in various examples, may be capable of providing anumber of advantages. In general, the disclosure may allow a user, e.g.,a clinician, to focus on desired tissue changes that should occur fromthe stimulation therapy instead of stimulation parameters that need tobe found in order to create the desired therapy result. In other words,the clinician may specify a desired result and permit a programmingsystem to select parameters to achieve the result. This approach mayreduce the time required for trial and error during stimulation therapyprogramming sessions. In addition, the user interface may use fieldshapes that indicate in what manner the tissue will be affected by thestimulation. For example, an activation field shape may indicate whichtissue near the cathode will be activated while an inhibition fieldshape may indicate which tissue near the anode will be inhibited. Theuser may be able to adjust the field shapes until the final field shapecombinations and resulting stimulation field are representative of thedesired stimulation therapy.

The details of one or more embodiments of the disclosure are set forthin the accompanying drawings and the description below. Other features,objects, and advantages of the disclosure will be apparent from thedescription and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual diagram of an implantable electrical stimulatorfor delivering stimulation therapy and an associated externalprogrammer.

FIG. 2 is a block diagram of an external programmer that facilitatesuser directed programming of stimulation therapy.

FIG. 3 is a block diagram of an implantable electrical stimulation thatgenerates electrical stimulation and delivers the stimulation therapybased upon one or more programs.

FIG. 4 is a conceptual illustration of a user interface that facilitatesprogramming of electrical stimulation therapy.

FIGS. 5A-5D are conceptual illustrations of user interfaces that includedifferent stimulation regions for placing stimulation fields.

FIG. 6 is a conceptual illustration of a user interface with a toolbarthat allows a user to create shape icons.

FIGS. 7A and 7B are conceptual illustrations of a user interface withactivation and current density icons and a view of delivered currentdensity to a patient.

FIGS. 8A and 8B are example activation and current density icons withdirection indicators.

FIGS. 9A and 9B are conceptual illustrations of a user interface withactivation and neuron model icons and a view of neuron activation.

FIGS. 10A and 10B are conceptual illustrations of a user interface withan activation icon and a view of stimulation depth region activation.

FIGS. 11A and 11B are conceptual illustrations of activation andinhibition icons for electrode polarity.

FIG. 12 is a conceptual illustration of a user interface with anactivation and inhibition icons for multiple locations within thestimulation region.

FIGS. 13A-13C are example electrode configurations for specific leadgroups.

FIGS. 14A-14D are conceptual illustrations of electrode configurationsand corresponding activation icons and neuron models.

FIGS. 15A-15D are conceptual illustrations of electrode configurationsand corresponding current density depths.

FIGS. 16A-16D are conceptual illustrations of electrode configurationsand corresponding activation depths.

FIG. 17 is a conceptual illustration of a split sequence for a group ofactivation and inhibition icons.

FIGS. 18A and 18B are conceptual illustrations of example activation andinhibition icons with pivot points to move and resize the icons.

FIG. 19 is a conceptual illustration of a user interface with activationand inhibition icons moved within the stimulation region.

FIGS. 20A-20B are conceptual illustrations of move sequences for a groupof activation and inhibition icons.

FIG. 21 is a conceptual illustration of a user interface with activationand inhibition icons rotated within the stimulation region.

FIGS. 22A-22B are conceptual illustrations of rotate sequences for agroup of activation and inhibition icons.

FIG. 23 is a conceptual illustration of a user interface with activationand inhibition icons resized within the stimulation region.

FIG. 24 is a conceptual illustration of a resizing sequence for a groupof activation and inhibition icons.

FIG. 25 is a conceptual illustration of a user interface with activationand inhibition icons stretched within the stimulation region.

FIGS. 26A-26B are conceptual illustrations of stretch sequences for agroup of activation and inhibition icons.

FIGS. 27A and 27B are conceptual illustrations of different electrodecombinations to drive activation deeper within the tissue of a patient.

FIGS. 28-29 are conceptual illustrations of user interfaces that allowsa user to select a field shape, place the field shape within astimulation region, and modify the field shape.

DETAILED DESCRIPTION

The user interface described herein facilitates the programming ofstimulation parameters by focusing the efforts of the clinician to thedesired stimulation field produced by electrical stimulation instead ofthe individual parameters needed to produce the stimulation field. Theuser interface comprises a stimulation region that may include arepresentation of the implanted electrical leads, a representation of atemplate, a representation of a patient image, or any otherrepresentation to aid the clinician in defining the stimulation field.The user interface may also include at least one toolbar, which may bepresented adjacent to the implanted electrical leads. The clinician mayselect field shapes from the toolbar, and drag the field shapes to adesired location over the implanted electrical leads. The field shapes,so located, represent the stimulation field that will be produced bystimulation parameters generated to match the field shapes andlocations. In addition, the clinician may select actions or icons fromthe toolbar that modify or move the field shapes in the stimulationregion to create a stimulation field desired by the clinician. Aprogrammer may generate stimulation parameters as needed to match thestimulation field created by the clinician.

The field shapes that represent the overall stimulation field may be indifferent forms to show alternative representations/effects of thefield. For example, the field shapes may illustrate current density,neural or other activation and/or inhibition, a neuron model, or othermethods of displaying the stimulation field or its effect on patientduring stimulation therapy. In this manner, the clinician may not needto manually set stimulation parameters such as the electrodeconfiguration, pulse width, pulse rate, and voltage or currentamplitude. Instead, the programmer automatically determines thestimulation parameters based upon the field shapes that make up theoverall stimulation field created by the user, and the locations of thefield shapes. In some embodiments, the clinician may have the ability toselect a manual mode for direct selection of stimulation parameters,either alone, or in conjunction with parameters selected automaticallyby the programmer according to field shapes specified by the clinician.Allowing the user to program stimulation therapy by viewing anestimation of the resulting therapy with a stimulation field beforeapplying the therapy to a patient may reduce the knowledge, training,and time needed to select a stimulation program sufficient toeffectively treat the patient.

The disclosure presents various programming methods. In some examples,the methods may include presenting on a display at least one view of arepresentation of an implantable lead within a stimulation region andpresenting on a display at least one icon that is used to specifyadjustments to a stimulation field. The method may also includereceiving user input defining and locating the stimulation field withthe at least one icon and generating electrical stimulation parametersbased upon the user input. The disclosure also contemplates programmingdevices, including programming devices that implement methods asdescribed herein, as well as systems including one or more programmingdevices and one or more electrical stimulators programmed using suchdevices. The electrical stimulators may be implantable and may deliverelectrical stimulation in the form of electrical stimulation pulses orsubstantially continuous electrical stimulation waveforms. In addition,the disclosure contemplates stimulators equipped to deliver stimulationvia various electrode configurations and with various parameters asdescribed herein, including stimulators capable of deliveringstimulation that corresponds to various field shapes defined by a uservia a graphical user interface as described in this disclosure.

FIG. 1 is a conceptual diagram of an example system 10 comprising animplantable electrical stimulator 14 for delivering stimulation therapyand an associated external programmer 20. As shown in FIG. 1,implantable stimulator 14 is coupled to electrical leads 16A and 16B(collectively “leads 16”). Implantable stimulator 14 is implanted withina patient 12. Leads 16 are implanted along the length of spinal cord 18such that electrical stimulation from leads 16 affects the spinal cord.Programmer 20 is used by a user to create one or more customizedprograms that define the electrical stimulation delivered to patient 12by stimulator 14. Programmer 20 communicates with stimulator 14 to, forexample, provide stimulator 14 the programs created using theprogrammer. Stimulator 14 generates and delivers electrical stimulationtherapy according to the programs to treat a variety of patientconditions such as chronic pain.

The creation of a stimulation field with field shapes, or field shapeicons, is primarily described herein with respect to spinal cordstimulation (SCS) therapy. However, the invention is not limited toembodiments that provide SCS. Rather, embodiments according to theinvention may be directed to stimulation of any tissue within patient12. For example, embodiments may provide spinal cord stimulation (SCS),deep brain stimulation (DBS), gastric stimulation, pelvic nervestimulation (e.g., sacral, pudendal, iliohypogastric, ilioinguinal,dorsal, peritoneal, or the like), peripheral nerve stimulation,peripheral nerve field stimulation (e.g., occipital, trigeminal, or thelike), or any other type of electrical stimulation therapy. While theconfiguration and/or location of a stimulator 14 and/or leads 16 may bedifferent depending on the specific application of system 10, programmer20 may still function according to its description herein.

Stimulator 14 delivers stimulation according to a program, i.e., a setof values for a number of parameters that define the stimulationdelivered according to that stimulation program or parameter set, whichmay include voltage or current pulse amplitudes, pulse widths, pulserates, and information identifying which electrodes (not shown) on leads16 have been selected for delivery of pulses, and the polarities of theselected electrodes, i.e., an electrode configuration. Each set ofstimulation parameters is stored as a program in stimulator 14 orprogrammer 20. Multiple programs may be stored to allow patient 12 toevaluate multiple programs during the course of therapy, or use specificprograms during certain activities such as sleeping, sitting, orwalking. Stimulator 14 may even track the usage of each program, orprovide changes to the currently used program based upon patientfeedback, a malfunction of lead 16A or 16B, or any other reason forchanging the program.

Leads 16 may be any type of electrical stimulation lead with one or moreelectrodes (not shown) along the length and/or proximate to the distalends of the lead. Leads 15 may also include a connector at the proximateend of the leads. The electrodes may be “ring electrodes,” e.g.,electrodes that create a cylinder around the exterior of leads 16. Leads16 may, in some examples, be in the form of paddle leads or other shapesdifferent than that shown in FIG. 1. In addition to embodimentsincluding two leads 16, as illustrated in FIG. 1, other embodiments mayinclude only one or more than two leads 16 implanted within patient 12.

In other examples, leads 16 may include a complex electrode arraygeometry. A complex electrode array geometry may include partial ringelectrodes, segmented electrodes, or other electrodes that are limitedto a portion of the perimeter of the lead. A complex electrode arraygeometry may allow the clinician to target a stimulation field at acertain circumferential position around the perimeter of the lead,instead of producing a stimulation field around the entire perimeter, asis typical with ring electrodes. The production of a precise stimulationfield may improve stimulation efficacy and reduce adverse side effectsresulting from stimulation of untargeted tissues.

Programmer 20 is an external programmer that can be used to createstimulation programs using the user interface (not shown) provided bythe programmer. Programmer 20 may be either a clinician programmer or apatient programmer, but programmer 20 will be generally described as aclinician programmer herein. In some embodiments, a patient programmermay have limited functionality or certain safeguards that preventpatient 12 from causing injury with stimulator 14. In the case of aclinician programmer, the clinician interacts with programmer 20 tocreate a visual representation of a stimulation field, utilizing thefield shapes and other tools described herein, that may treat patient12. Programmer 20 then generates stimulation parameters automaticallybased upon the created stimulation field and transmits the stimulationparameters to stimulator 14 as a single program. For example, thecreated stimulation field representation may be mapped to or correlatedwith the stimulation parameters, e.g., electrode configuration(combination and polarities), pulse rate, pulse width, amplitude, andduration (if applicable) necessary to produce the stimulation field inthe patient.

Programmer 20 communicates with stimulator 14 via wirelesscommunications during initial programming of stimulator 14, furtherfollow-up programming, or retrieving data collected by the stimulator.Wireless communication between stimulator 12 and programmer 20 may occurusing radio frequency (RF) telemetry techniques known in the art.Furthermore, wireless communications between stimulator 14 andprogrammer 20 may occur using any of a variety of local wirelesscommunication techniques, such as RF communication according to theInstitute of Electrical and Electronic (IEEE) 802.11 or Bluetoothspecification sets, infrared communication according to the InfraredData Association (IRDA) specification set, or other standard orproprietary communication protocols.

As an example, programmer 20 may be embodied as a hand-held computingdevice that the clinician may easily transport throughout the clinic,hospital, or any other location. However, programmer 20 mayalternatively be embodied as any type of device. In various embodiments,programmer 20 may be a tablet-based computing device, a personal digitalassistant (PDA), a notebook computer, a desktop computing device, aworkstation, or any other computing device capable of the functionsdescribed herein. Programmer 20 may be used by the clinician in aclinic, and additionally or alternatively used by patient 12 or acaregiver at the patient's home, the clinic, or other facility ofpatient 12.

FIG. 2 is a block diagram further illustrating example externalprogrammer 20 that facilitates user directed programming of stimulationtherapy. As shown in FIG. 2, programmer 20 may include a processor 22,memory 24, user interface 26, input/output module 28, telemetry module30, and power source 32. Processor 22 controls the functioning ofprogrammer 20 in the manner described herein according to theinstructions stored in memory 24. A user interacts with user interface26, and data is sent to and received from stimulator 14 via telemetrymodule 30. The clinician may also use input/output module 28 to exchangedata with other computing devices without using telemetry module 30.Power source 32 may be a battery that provides power to some or all ofthe components of programmer 20.

In the example of FIG. 2, memory 24 stores programs, including thosecreated by the clinician or other user, e.g., patient 12, using thetechniques described herein. As discussed above, the programs stored inmemory 24 specify electrode configurations (combinations andpolarities), and other stimulation parameters. Processor 22 may downloadthe programs to implantable stimulator 20 via telemetry module 30.Memory 24 may include any volatile, non-volatile, magnetic, optical, orelectrical media, such as a random access memory (RAM), read-only memory(ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM(EEPROM), flash memory, or any other digital media.

In addition to stimulation programs, memory 24 may store instructionsthat support the operation of programmer 20 through processor 22.Processor 22 may use the instructions stored within memory 24 to controluser interface 26, how stimulation fields are created, how programs arecreated, communications via telemetry module 30, data transfer viainput/output module 28, and power management with power source 32.Memory 24 may include separate sub memories to store differentinformation in some examples, while other examples of memory 24 may onlyinclude one memory.

The clinician interacts with processor 22 via user interface 26 in orderto identify efficacious electrode configurations and other stimulationparameters as described herein. Processor 22 may provide a graphicaluser interface (GUI) (not shown in FIG. 2), via user interface 26 tofacilitate interaction with the clinician. Processor 22 may include amicroprocessor, a microcontroller, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field-programmablegate array (FPGA), or other discrete or integrated logic circuitry. Userinterface 26 may include one or more input media, such as a keyboard,keypad, mouse or other pointing device, or a touch screen display. Inaddition, user interface 26 may include output media such as a display,speaker, lights, audible alerts, or tactile alerts.

Processor 22 controls stimulator 14 via telemetry module 30 to testcreated stimulation programs by controlling the stimulator to deliverstimulation to patient 12 via the selected electrode combinations andaccording to the other parameters specified by the programs. Inparticular, processor 22 transmits programming signals to implantablestimulator 14 via telemetry module 30. Processor 22 may send one or moreprograms to stimulator 14 and the stimulator may deliver therapyaccording to one of the programs without further input from programmer20. However, processor 22 may communicate with stimulator 14 inreal-time via telemetry module 30 in order to immediately observe theprogramming change in patient 12. In some cases, changes to stimulationmay not be immediately evident. In such cases, a change may be activatedand evaluated over a period of minutes, hours, or days before anotherchange is initiated.

Finalized programs may be transmitted by processor 22 via telemetrymodule 30 to stimulator 14. Alternatively, programs may be stored instimulator 14 and modified or selected using instructions transmitted byprocessor 22 via telemetry module 30 to the stimulator. The one or moreprograms may be stored in a memory of stimulator 14 or anotherprogrammer used by patient 12, e.g., a patient programmer. In any case,stimulator 14 may selectively use any of the stimulation programscreated by the clinician using the field shapes and the relatedtechniques described herein. Either the clinician or patient 12 mayadjust the stimulation programs over time or create new stimulationprograms in order to find efficacious stimulation programs withacceptable or no side effects.

Again, programmer 20 may be provided in the form of a handheld device,tablet computer, portable computer, laptop computer, personal desktopcomputer, or workstation. In each case, programmer 20 provides userinterface 26 to a clinician or patient. User interface 26 may include orprovide a graphical user interface (UI), and include any combination ofaudible, visual, and tactile input and output media. The clinician orpatient 12 interacts with user interface 26 to program stimulationparameters for implantable stimulator 14 via external programmer 20.Hence, various aspects of user interface 26 described herein may beprovided via a clinician programmer, a patient programmer, or both.

FIG. 3 is a block diagram of an implantable electrical stimulator 14that generates electrical stimulation and delivers the stimulationtherapy based upon one or more programs. Stimulator 14 may deliverstimulation via electrodes 50A-D of lead 16A and electrodes 50E-H oflead 16B (collectively “electrodes 50”). Electrodes 50 may be ringelectrodes. Alternatively, electrodes 50 may be pad electrodes arrangedon a paddle lead, or have more complex electrode geometries. Forexample, electrodes 50 may be segmented electrodes arranged in segmentsor sections at different arcuate sections around the circumference of anaxial or cylindrical lead. In some cases, ring electrodes, padelectrodes, partial ring electrodes, and/or segmented electrodes may becombined on a single lead. The configuration, type and number ofelectrodes 50 and leads 16 illustrated in FIG. 3 are merely exemplary.For bilateral or multi-lateral stimulation, multiple leads may beprovided. In the example of FIG. 3, two leads 16A and 16B are shown.

In the example of FIG. 3, electrodes 50 are electrically coupled to aswitch device 40. Switch device 40 is able to selectively couple each ofthe electrodes to circuits within stimulator 14 under the control of aprocessor 34. For example, through switch device 40, processor 34 mayselectively couple electrodes 50 to a pulse generator 38. In otherexamples, switch device 40 may not be necessary if separate pulsegenerators 38 are provided for and coupled to each electrode 50.Additionally, some embodiments may include a plurality of pulsegenerators 38 selectively coupled to any of electrodes 50, which may bemore numerous than the pulse generators, by one or more switch devices40.

Pulse generator 38 may deliver electrical pulses to patient 12 via atleast some of electrodes 50 under the control of a processor 34, whichcontrols pulse generator 38 to deliver the pulses according to thestimulation parameter values of a current program. Processor 34 controlsvia which of electrodes 50 the pulses are delivered, as well as thepolarity of the pulses at each of the selected electrodes, by itscontrol of switch matrix 40, or its selective control of respectivepulse generators in embodiments in which electrodes are associated withrespective pulse generators. The programs used by processor 34 tocontrol delivery therapy by pulse generator 38 may be received via atelemetry module 42 and/or stored in memory 36. In some examples, inaddition or instead of pulse generator 38, stimulator 14 may include oneor more stimulation generators that produce continuous signals, such assine waves.

Processor 34 may include a microprocessor, a controller, a DSP, an ASIC,an FPGA, discrete logic circuitry, or the like, or any combination ofone or more of the foregoing devices or circuitry. Memory 36 may includeany volatile, non-volatile, magnetic, optical, or electrical media, suchas RAM, ROM, NVRAM, EEPROM, flash memory, and the like. In someembodiments, memory 36 stores program instructions that, when executedby processor 34, cause stimulator 14 and processor 34 to perform thefunctions attributed to them herein.

Telemetry module 42 may include components to send data to and/orreceive data from programmer 20. Telemetry module 42 may utilize anynumber of proprietary wireless communication protocols known in themedical device arts. Furthermore, telemetry module 42 may use radiofrequency (RF) signals according to 802.11, Bluetooth or other shortrange wireless technologies. Power source 44 may be a rechargeable ornon-rechargeable battery. A rechargeable battery may be recharged viainductive coupling with programmer 20 or another external device capableof recharging power source 44. Power source 44 may employ an energyscavenging device or heat device that uses patient 12 motion orgenerated heat to recharge the rechargeable battery. Alternatively,power source 44 may also require inductive coupling to an outside energysource at any time that stimulator 14 is to operate, i.e., may storeinadequate power for non-coupled operation of stimulator 14.

FIGS. 4-29 are conceptual illustrations of user interfaces thatfacilitate user programming of electrical stimulation therapy. The userinterfaces may be presented via a display and other input or outputmedia associated with programmer 20. Field shapes are icons that may beused by the clinician to specify what the resulting stimulation fieldshould look like for patient 12. Field shapes may refer to differentaspects of the stimulation field, depending on the preference of theclinician. For example, the field shapes may be representative of acurrent density, an activation/inhibition function, and/or a neuronmodel. The current density field shape illustrates how the electricalcurrent from the electrical field produced by electrodes 50 propagatesor is expected to propagate through the tissue of patient 12 aroundleads 16. The activation function field shape illustrates which portionof the tissue will be activated and/or inhibited by the electrical fieldaround electrodes 50. Activation is generally caused around the cathode(electrons leaving that particular electrode designated as the cathode)and inhibition is generally caused around the anode (electrodes reachingthat particular electrode designated as the anode). In addition, thefield shapes may illustrate a neuron model, or how neurons withinstimulated tissue would actually be affected by the stimulation therapy.The field shapes, and resulting stimulation field, may be adjusted toillustrate any aspect of the stimulation therapy that would provideinsight to the clinician for programming the stimulation therapy.

FIG. 4 shows a graphical user interface (GUI) 52 that includes a sideview 61 and axial cross-section, i.e., a depth view 62, of twoimplantable leads in a stimulation region 58. Lead side view 64, leadside view 66, lead axial section 88, and lead axial section 90 may berepresentative of leads 16 described in FIGS. 1 and 3. GUI 52 isprovided in screen 54 and contains field shape selection menu 56 andfield manipulation tool menu 60 located on either side of GUI 52.

Field shape selection menu 56, e.g., “Shapes” located on the leftprovides example field shapes that the clinician may select and dragover to a location within stimulation region 58 proximate to the leadrepresentations, e.g., proximate to lead side views 64 and 66. In theillustrated example, field shape selection menu 56 comprises fiveselectable “groups” of one or more field shapes, including, for example,field shapes 68A and 68B, which are collectively form and are referredto as a “field shape group 68.” Each of field shape groups 68, 70, 72,74, and 76 are illustrative of an activation function. In variousembodiments, field shape selection menu 56 may include any number ofselectable field shape groups.

Striped field shapes may indicate activation of the tissue while shadedfield shapes may indicate inhibition of the tissue. Activation of tissuegenerally refers to the initiation of action potentials within nervetissues. Activation of tissue may occur near electrodes 50 configured ascathodes. Conversely, inhibition of tissue generally refers to theprevention of activating action potentials within adjacent nervetissues. Inhibition of tissue may occur near electrodes 50 configured asanodes. Activation and inhibition of tissue is thereby generated in partby the location of anodes and cathodes implanted within patient 12.

However, these particular visual pattern choices (striped and shaded)are for purposes if illustration and example, and should not beconsidered limiting. In other embodiments, for example, different colorsmay indicated activation and inhibition, e.g., red field shapes mayindicate activation of tissue and blue shapes may indicate inhibition.Activation, inhibition, or locations or states in between activation andinhibition, may be indicated by any color, shading, symbol, orindication. In addition, field shapes may be of any specific shape,e.g., circular, oval, square, or rectangular, that corresponds toelectrodes 50, the type of therapy, or other factors. In the example ofFIG. 4, field shape groups 68, 70, 72, 74, and 76 comprise circularfield shapes.

Multiple field shapes may be shown in the shapes toolbar to provideflexibility to the clinician. As shown, five different field shapegroups 68, 70, 72, 74, and 76 are provided to the clinician.Combinations of field shapes shown to the clinician may includeactivation and inhibition pairs (field shape groups 68 and 76), singleactivation field shapes (field shape group 72), single inhibition fieldshapes (field shape group 74), and multiple activation and inhibitiongroups (field shape group 70), where any of the field shapes may beoriented in different directions. Field shape group 68 comprises avertically oriented activation/inhibition pair, field shape group 70comprises two inhibition field shapes and one activation field shapebetween them, field shape group 72 comprises a single activation fieldshape, field shape group 74 comprises a single inhibition field shape,and field shape group 76 comprises a horizontally orientedactivation/inhibition pair. The clinician may interface with GUI 52 toclick a desired field shape group and drag it to a position withinstimulation region 58. The position of each field shape may correspondwith a direct location of one of electrodes, or the position of eachfield shape may be offset from one or more electrodes of lead side views64 and 66. As an example, field shape 70 may be dragged over lead sideview 64 in stimulation region 58 such that each field shape 70A, 70B,and 70C covers one of an adjacent vertical trio of electrodes of leadside view 64. In other examples in which a field shape does not directlycorrelate with the center of an electrode, i.e., it is offset fromcenter, simultaneous activation of two or more electrodes at two or moredifferent current or voltage amplitudes may be used to effectivelycenter the actual stimulation field in the desired location as shown bythe field shape. Processor 22 determines the stimulation parameters thatwill result in the actual stimulation field based upon the placement ofthe field shapes. If a placement of a field shape is not achievablegiven a lead geometry and/or pulse generator 38 capability, processor 22may notify the user of this error and/or automatically adjust the fieldshape to the nearest achievable location within stimulation region 58.

Field shape manipulation tool menu 60 is located on GUI 52 as well,e.g., right of stimulation region 58. Field shape manipulation tool menu60 provides icons that allow the clinician to manipulate and adjust anyof the field shapes placed within stimulation region 58. Field shapemanipulation tool menu 60 may include icons such as move icon 78, rotateicon 80, stretch icon 82, grow icon 84, and shrink icon 86. Theclinician may select one or more field shape groups from field shapeselection menu 56 and select an action from field shape manipulationtool menu 60 that accordingly changes one or more of the field shapesplaced within stimulation field 58. Alternatively, each action fromfield shape manipulation tool menu 60 may be selectively applied to allfield shapes within stimulation region 58 that define the stimulationfield for therapy.

As an illustration, an field shape group 68 may be selected from fieldshape selection menu 56, dragged into stimulation region 58, and placedover a desired pair of electrodes of lead side view 64, e.g., using astylus or other pointing tool. Then, the user may select the grow icon84 from the field shape manipulation tool menu 60 to increase the sizeof one or both of field shapes 68A and 68B in stimulation region 58 to adesired size for the represented activation and/or inhibition regions.For example, selection of grow icon 84 may reveal a command structurethat permits the user to enter a size, drag a perimeter of one or bothof field shapes 68A and 68B to increase their size, select an arrow inthe direction of the growth of the field shape, or select an incrementalinput, like a plus or up arrow to incrementally increase the sizeaccording to a proportional or preselected fixed magnitude.Alternatively, growing or shrinking of a field shape may be realized byup/down arrows, plus/minus icons, or a slider bar to increase anddecrease the size of the field shapes. If multiple sets of field shapesare presented in stimulation region 58, the user may be required toselect one of them, e.g., with a stylus, in order to apply to theappropriate tool from the field shape manipulation tool menu 60 tomanipulate a field shape or selected set of field shapes or field shapegroups. In some examples, more or less icons may be available to theclinician to perform certain actions. For example, depending on theplacement of selected field shapes, processor 22 may remove orinactivate one or more icons of field shape manipulation tool menu 60because that action cannot be performed.

In addition to the actions shown in field shape manipulation tool menu60 of GUI 52, other icons may be presented that allow the clinician toperform different actions. For example a mirror icon may be providedthat allows the clinician to select a field shape or field shape groupand flip it about a vertical axis, horizontal axis, or oblique axis. Theclinician may also be able to create new actions for use with GUI 52,save them to an action library, and load them into the field shapemanipulation tool menu 60 when desired. Field shape manipulation toolmenu 60 may also have a copy and paste action that allows the clinicianto duplicate field shapes or field shape groups within stimulationregion 58 and place it at another location. In other examples, GUI 52may allow the clinician to delete one or more field shapes instimulation region 58. For example, the clinician may simply drag theunwanted field shape or field shape group off of stimulation region 58to make it disappear, or GUI 58 may include a trash can or other areathat the clinician drags the field shape or group into to delete it fromthe stimulation region.

In other examples, the clinician may be able to adjust the field shapeprior to placing the field shape within stimulation region 58. In thismanner, the clinician may select an icon within manipulation tool menu60 that sets a default field shape size or position that is placedwithin stimulation region 58. In addition some icons of manipulationtool menu 60 may be deactivated until a field shape is placed withinstimulation region 58. For example, GUI 52 may only provide grow icon 82after a field shape is selected and placed within stimulation region 58.

GUI 52 may also include options that allow the clinician to change thelayout of stimulation region 58, field shape selection menu 56, or fieldshape manipulation tool menu 60. For example, the clinician may wantboth menu 56 and menu 60, e.g., any toolbars, on one side of stimulationregion 58. Alternatively, the clinician may be able to zoom into or outof stimulation region 58 to get a closer view of one or more fieldshapes in relation to lead side views 64 and 66. GUI 52 may also allowthe clinician to view, in conjunction with the stimulation field shapes,a scale of stimulation region 58, markers indicating anatomical areas ofpatient 12, an anatomical region of patient 12, e.g., a tissue image, ananatomical atlas, a somatotopic map, or any other indication to theclinician that may be useful for visualizing the effect of stimulationfields while programming stimulation therapy.

In addition to side view region 61, stimulation region 58 may includedepth view region 62 that includes lead axial views 88 and 90.Stimulation depth view region 62 may orient the clinician to the radialmagnitude of field shapes that cannot be shown by side view region 61 ofstimulation region 58. Accordingly, stimulation depth view region 62 maybe an end view looking down the length of a lead, such that the effectof the stimulation field lateral to the lead can be readily observed interms of depth of penetration into surrounding tissue. In other words,the clinician may be able to view an axial cross-section representationof leads 16. This depth view may be especially important in the case ofleads with segmented or asymmetric electrode profiles such thatstimulation is not symmetric about the longitudinal axis of lead 16.

A marker may be shown in side view region 61 that indicates thelongitudinal position of lead side views 64 and 66 that the stimulationdepth view region 62 is illustrating. In some examples, processor 22will automatically determine the longitudinal location for stimulationdepth view region 62, e.g., at the location of the greatest radialmagnitude of the stimulation field. Alternatively, the clinician mayselect the longitudinal location of stimulation depth view region 62 andmove along the length of lead side views 64 and 66 to view other depthsof the represented leads. This may be represented by a line or plane inside view region 61. In some examples, GUI 52 may represent depth of thefield shapes, i.e., the extent to which the field extends outwardtransversely relative to a longitudinal axis of the lead side views 64and 66, without the use of stimulation depth region 62. For examples, acontour view, a view where color intensity correlates to depth, or aview where deeper stimulation is more opaque than shallower stimulationmay be used to represent depth of the stimulation. In other cases, thelocations of side view region 61 and depth view region 62 in stimulationregion 58 may be switched to allow stimulation depth view region 62 tobe the primary area where the clinician places field shapes.

In some examples, the types of fields being shown to the clinician maybe different between side view region 61 and depth view region 62. Forexample, activation/inhibition functions may be shown in side viewregion 61 while current density may be shown in depth view region 62.GUI 52 may automatically determine the field type shown to theclinician, or the clinician may select the field types to be shown. Theclinician may select these types directly from GUI 52 or within a menuthat the clinician may open.

GUI 52 as illustrated in FIG. 4 and described throughout thisspecification, generally may be realized by any combination of displaytechnology and selection media. Examples include display screens andvarious combinations of hard keys, soft keys, buttons, touchscreenmedia, and the like, as well as any of a variety of pointing devicessuch as a stylus, mouse, trackball, scroll wheel, joystick, or the like.In some examples, a touchscreen and stylus may be particularly useful inselecting and manipulating features of GUI 52. Also, in some examples,programmer 20 may include various buttons and a keypad such as analphanumeric keypad. The foregoing structure is described for purposesof illustration and without limitation to GUI 52 implementation.

FIGS. 5A-5D show example GUIs 52A-52D illustrating differentconfigurations for stimulation region 58 along with field shapeselection menu 56 and field manipulation tool menu 60. Similar to GUI 52of FIG. 4, GUIs 52A-52D include one of stimulation regions 58A, 58B,58C, and 58D (collectively “stimulation regions 58”) that allow the userto define the stimulation field with field shapes from field shapeselection menu 56. FIG. 5A shows GUI 52A that includes stimulation field58A with lead side view region 61A similar to lead side view region 61of FIG. 4, and a lead depth view region 62A similar to lead depth viewregion 62 of FIG. 4.

FIG. 5B displays GUI 52B which includes stimulation region 58B,including side view and depth view regions 61B and 62B. Stimulationregion 58B does not include representations of the leads implantedwithin patient 12. Instead, the clinician attempts to place field shapesat desired locations of tissue within patient 12. Using GUI 52B, one ormore markers of tissue location may be provided to orient the clinician.

FIG. 5C illustrates GUI 52C, which shows representations of leads 16 inthe stimulation region 58C (side view and depth view regions 61C and62C), but the leads are faded and shown in the background to emphasizethe importance of the location of the field shape relative to patienttissue when programming with field shapes from field shape selectionmenu 56.

In an alternative example, FIG. 52D shows GUI 52D including an actualimage of an anatomical region of patient 12 within side view region 61D.The image of side view region 61D may illustrate electrodes of implantedleads 16. The image may be a fluoroscopic image, x-ray image, MRI image,or any other image of the patient in the pertinent region forstimulation. The image may provide an anatomical reference to facilitateplacement of field shapes from field shape selection menu 56 at adesired anatomical location by the clinician. In the example of FIG. 5D,side view region 61D includes the actual image, while depth view region62D does not. In various embodiments, either or both of the sub regionswithin stimulation region 58D may include an actual image of leads 16and/or the anatomy of patient 12.

In any of GUIs 52A-52D shown in FIGS. 5A-5D, a representation of theanatomy of patient 12 may be provided in the respective stimulationregion 58 to orient the clinician. The anatomical representation may bean image of the actual anatomy of patient 12 and the relation ofimplanted leads 16 to the represented anatomical region. In this manner,the clinician may be able to accurately place field shapes over theparticular anatomical region that the clinician desires to stimulate.For example, the clinician may specify which tissue should be activatedand inhibited with the activation/inhibition function type of fieldshapes. The anatomical region may be an image created by any imagingmodality available to the clinician. For example, the anatomical regionmay be acquired through the use of a magnetic resonance imaging (MRI)device, an X-ray device, a computed tomography (CT) device, a positronemission tomography (PET) device, or any other suitable imagingmodality. Alternatively, the anatomical region may be a representativeregion that is not obtained from the actual patient, for example aschematic image or a standard reference image from an available atlas ofimages.

Programmer 20 may map or configure the stimulation region 58 based onthe location of leads 16 and electrodes 50 within patient 12. Theclinician either manually enters the coordinates of leads 16 and/orelectrodes 50 into programmer 20 to create stimulation region 58, or thecoordinates are automatically mapped via an imaging modality. While theclinician may use stimulation region 58 without mapping the location ofleads 16 to the stimulation region, the generated stimulation parametersfor the stimulation field created by the clinician may be inaccurate andineffective in treating patient 12.

FIG. 6 is another example GUI 99 for programming stimulation therapywith field shapes from field shape selection menu 100. GUI 99 is similarto GUI 52 of FIG. 4, and provides stimulation region 58 with side anddepth view regions 61 and 62 including representations of leads 16,along with field shape selection menu 100 and field shape manipulationtool menu 60. Field shape selection menu 100 may include field shapegroups 102 and 104. In addition to available field shapes in field shapeselection menu 100, managing icons are provided to offer customizationof field shapes to the clinician. Managing options may include createnew icon 106, name icon 108, and split icon 110.

Split icon 110 may be used to divide a selected field shape group (e.g.,selected with a stylus or other pointing device) into two groups, eachcontaining one or more field shapes. For example, field shape group 102may be split into two identical field shape groups. In some examples, amerge icon (not shown) may be provided to combine two or more fieldshapes or field shape groups into a single field shape group containingmultiple field shapes. The clinician may select create new icon 106 whenthe clinician desires to create a new field shape or group that is notpresent in field shape selection menu 100.

The clinician may attach a name to a certain field shape or field shapegroup by selecting the name icon 108. Field shapes or field shape groupsseparated by the split function may define multiple stimulation fieldsdelivered to tissue of patient 12 using interleaved pulse trains (e.g.,sets of stimulation pulses) from one stimulus generator or multiplesimultaneous pulses or signals from multiple stimulus generators.Therefore, splitting a field shape may involve breaking one pulse trainor signal into two or more interleaved pulse trains or signals,respectively. Merging two or more field shapes may cause the electrodecombinations being delivered in multiple pulse trains or signals tochange into an equivalent (or near equivalent) single field shape orfield shape combination to be delivered in a single pulse train.

In addition, GUI 99 may allow the clinician to save newly created fieldshapes, field shape groups, combinations, or entire stimulation fieldsas positioned in stimulation region 58. In this manner, the clinicianmay be able to store multiple preset field shapes, field shape groups,or stimulation fields in programmer 20 so that the clinician does notneed to start from scratch with each session for patient 12 or otherpatients. The saved field shapes may be field shapes or field shapegroups that, from experience, the clinician knows generally provideefficacious therapy to patient 12. In other examples, GUI 99 may have alibrary icon (not shown) that the clinician may select to browse savedfield shapes and field shape groups, and move selected library itemsinto field shape selection menu 100. A library may be common to multiplepatients, or preserved specifically for a single patient 12, or commonto a specific lead or device family. Field shapes may be named by theclinician or assigned names automatically by programmer 20. Names may bedescriptive of a particular field shape and may be edited by the user.

Generally, the field shapes available to the clinician via field shapeselection menu 100 are used by the clinician as a starting point forprogramming the stimulation therapy for patient 12. In other words, thefield shapes may not initially be tailored for certain therapy profilesor anatomy positions. The clinician drags one or more field shapes,e.g., field shape group 104, into stimulation region 58 and proceeds tomodify those field shapes with actions indicated by selection of iconsfrom field shape manipulation tool menu 60 in order to create astimulation field for the defines the desired therapy. In this manner,the clinician may be able to create customized therapy for patient 12with a reduction in time as compared with conventional selection ofindividual stimulation parameters, e.g., electrode configuration, pulsewidth, pulse rate, current amplitude, and voltage amplitude.

In some examples, field shapes of field shape selection menu 100 mayinitially be associated with a set of stimulation parameters, e.g.,program, that would produce each particular field shape. These programsmay include an electrode configuration (anodes and cathodes), pulsewidth, pulse rate, and voltage and/or current amplitude. However, as theclinician changes the location and size of the field shapes instimulation region 58, the initial set of stimulation parameters changesas needed to reproduce the stimulation field representation created bythe clinician. In particular, programmer 20 may automatically adjust thestimulation parameters to produce, at least approximately, thestimulation field representation created by the clinician.

FIGS. 7A and 7B show field shapes illustrating current density of theproposed/delivered stimulation. Like GUI 52 of FIG. 4, GUI 112illustrated in FIG. 7A includes stimulation region 58, including sideand depth view regions 61 and 62, as well as field shape manipulationtool menu 60, and a field shape selection menu 116. Field shapeselection menu 116 includes field shape 124 which displays an idealizedcurrent density and field shape 126 which displays an actual currentdensity field. In the example of FIG. 7A, field shape 124 isrepresentative of the shape of the current density field idealized intoa simple oval field shape and is provided in stimulation region 118. Theactual current density field shape 126 is a model of what the actualcurrent density of that field shape will be within patient 12. As shown,field shape 126 is a current density model based upon either a generaltissue characteristic, a typical spinal cord, a homogenous medium, ageneral anatomical model, or the actual tissue characteristics derivedfrom an image of the anatomy of patient 12. Field shapes may bepredefined and stored on programmer 20 or generated in real time as theclinician selects the field shapes. Field shape 126 shows that greatercurrent density is located near and in between two electrodes producingthe field shape.

Stimulation depth view region 62 displays the field depth 128 which isthe actual current density of field shape 124 placed by the clinicianover one of the leads in side view region 61. As shown, the currentdensity reduces with greater radial distance from active electrodes.Processor 22 may automatically determine the axial location along theleads shown in stimulation depth view region 62 to show in the maximumdepth of the current density. This axial location of field depth 128 maycorrespond to the greatest depth of the field model. GUI 112 may show amarker, dotted line, or some other indication in stimulation side viewregion 61 that indicates to the clinician the axial location shown instimulation depth view region 62. Alternatively, GUI 112 may allow theclinician to set the axial location of stimulation depth view region 62to identify depths of the stimulation field at various axial locationsof stimulation side view region 61. In addition to, or instead of, thetransverse stimulation depth view region 62, a depth view may beprovided that is longitudinal or axial in nature, e.g., oriented alongthe longitudinal axis of the leads. An associated marker line showingthe plane of cross section in stimulation side view region 61 may beused to indicate the location within the alternative longitudinal depthview.

Example modeled current densities are illustrated in the model views 136and 144 of FIG. 7B. Leads 130 are provided with example cathode 132 andanode 134 to correspond to field shape 124 of FIG. 7A. With an electrodelocated next to the spinal cord, the current density is greatest nearthe lead and decreases with radial distance away from the lead (orfurther within the spinal cord) as shown in a model views 136 and 144.Model view 136 shows subarachnoid space 138 and spinal cord 140 inrelation to current density model 142. Greater current density is shownby darker shading with decreasing current density indicated by lightershading as the current propagates away from the electrodes.Alternatively, greater current density may be shown by a “hotter” color,such as red, with decreasing current density indicated by progressively“cooler” colors from red to blue. For example, the current density rangemay run from red, to orange, to yellow, to green, and to blue toindicate the range of current density from highest to lowest.

Model view 144 includes spinal cord 146 with leads 148 placedlongitudinally along the spinal cord. Current density model 150 is alsoshown to indicate the generally oval shape of the current density modelcorresponding to the current density from two active electrodes of leads148. It should be noted that the actual current density is not perfectlyoval, but is more “peanut” shaped with a drop off in current densitybetween the two electrodes. While the current density is uniform at bothelectrodes, the effect on the adjacent tissue varies due to whether thetissue is closer to the anode or cathode of the active electrodes. Thisdifference may be similar to the activation of tissue and inhibition oftissue as described above. The “peanut” shape is one example of a fieldshape, and other non-regular field shapes may be yielded by otherstimulation parameter values.

FIGS. 8A and 8B provide an illustration for alternative current densityfield shapes 152 and 158 that may be provided by a user interface, i.e.,within a field shape selection menu of such user interface, according tothe invention. Field shape 152 of FIG. 8A is an idealized currentdensity field shape 154 with vector indication 156. Vector indication156 is an arrow that represents the direction current flows, from theanode to the cathode. Vector indication 156 indicates the average or netcurrent direction. In other embodiments, many discrete vectors may beshown to indicate current direction and magnitude in many points atonce. This vector field representation may be advantageous in assistingthe clinician in visualizing the outcome of a set of stimulationparameters. FIG. 8B shows field shape 158 which is an actual currentdensity field shape 160 that shows modeled current density, e.g.,representing higher to lower current density as progressively lightershading or changing color from red to blue, for example. Vectorindication 164 is an arrow that represents the direction that currentflows, which is from the anode to the cathode. In these cases, bothfield shapes 152 and 158 may be used to define a stimulation field inany stimulation region described herein and present the direction andmagnitude of the stimulation provided by a selected electrodeconfiguration.

With either of vector indications 156 or 164 on the field shapes 152 or158, respectively, the clinician may visualize the electrical context ofa selected field shape. This may be particularly useful when, forexample, the clinician selects that the field shape be rotated in thestimulation region of the GUI. In addition, the vector indications 156or 164 may have an impact on the clinician's decision to select another,or which other, field shape for the stimulation region. In otherexamples, field shapes indicating the vector of the electrical currentmay have an indication other than an arrow. For example, the vectorindication may be shown as plus and minus signs, a triangle,progressively bigger dots in a line, a shaded line, or any otherrepresentation.

Current density field shapes may be particularly beneficial to DBSapplications. Within the brain, the clinician may desire to limitcurrent density, or charge density, at specific locations within thebrain. The clinician may set a limit to the current density in whichfield shapes do not go beyond a preset current density limit or theclinician may simply view the current density applied to patient 12 viaa color of the field shape or a numerical indicator over the fieldshape. Of course, current density field shapes may also be used fortherapy applications other than DBS.

FIGS. 9A and 9B illustrate a GUI 166 with idealized activation function(“act func”) field shapes 178A and 178B (collectively “field shape group178”) and actual activation function field shapes 180A and 180B(collectively “field shape group 180”). GUI 166 is similar to GUI 52,and includes field shape selection menu 170, field shape manipulationtool menu 60, and stimulation region 58 (including side and depth viewregions 60 and 61). The clinician may click and drag any of field shapegroups 178 or 180 from field shape selection menu 170 into stimulationregion 58 to create a stimulation field. As shown, field shape group 178has been placed within stimulation region 58 and, more particularly,side view region 61. In addition to side view region 61, depth viewregion 62 is also provided to illustrate to the clinician the actualdepth of tissue of patient 12 that would be affected by the activationfunction from field shape group 178, e.g., as shown by the currentdensity representation 182. However, field depth may also be shown as anidealized or actual activation function. As shown in previous examples,GUI 166 also includes field shape manipulation tool menu 60 for alteringany field shapes placed in stimulation region 58.

The actual activation function field shapes, e.g., field shapes 180A and180B, are generated by modeling the activation of tissue from electricalstimulation. In particular, the activation shown in FIG. 9B are due toan anode 188 and a cathode 186 of leads 184. Corresponding actualactivation functions are shown with respect to spinal cord 190. Fieldshape 192 indicates activation of tissue while field shape 194 indicatesinhibition of tissue. The electromagnetic function for neuron activationmay be related to dV²/dZ². In other examples, the activation functionmay be attributed to other equations that closely model the activationtissue from the electrical stimulation. In the example described herein,the activation of tissue may be indicated by stripes, whereas theinhibition of tissue may be indicated by dots. Therefore, the clinicianmay desire to place dotted field shape 194 in the area of tissue thatthe clinician does not want activated. In other words, the clinician may“shield” certain tissue from stimulation and activation of that nervetissue. This may permit direct specification of “shielded” areas.

FIG. 10A shows example GUI 196 including a field shape selection menu200 that includes an idealized neuron activation field shape 208. GUI196 may be similar to GUI 52, and GUI 196 also includes field shapemanipulation tool menu 60, and a stimulation region 202 comprising aside view region 204 and a depth view region 206. The neuron activationfield shape 208 is also shown to be placed over one of the lead sideviews in side view region 204 according to the desires of the clinician.Corresponding with the view of side view region 204 and neuronactivation field shape 208, stimulation depth view region 206 providesfurther information for the clinician. In particular, stimulation depthview region 206 provides an axial cross section of both leads inconjunction with a cross-section of the adjacent spinal cord 210. Thecross-section of spinal cord 210 may be shown with white matterindicated by white portions and gray matter indicated by gray areas. Theneuron activation effect on the spinal cord is indicated by neuronactivation model 212. Neuron activation model 212 of spinal cord 210indicates to the clinician that only a portion of neurons in the whitematter is affected by the stimulation, whereas neurons in the graymatter are left unaffected.

The neuron activation field shape 208 or similar field shapes may beidealized, as shown in FIG. 10A, or the neuron activation field shapemay be an actual neuron activation that is modeled for patient 12. FIG.10B shows leads 214 which have cathode 216 and anode 218 to create thefield shape 208 and neuron activation model 212 of FIG. 10A. FIG. 10Balso shows a large activation model 220 that includes spinal cord 222and neuron activation model 224 over a portion of the spinal cord. Themodeling may be a finite element model and completed in real-time withprogrammer 20 or prior to use of the programmer. Either type ofidealized neuron activation field shape 208 or an actual neuronactivation field shape similar to neuron activation model 212 or 224 maybe provided to the clinician via field shape selection menu 200 of GUI196. The clinician may load particular field shapes that the cliniciandesires to use in stimulation region 202 using programmer 20.Alternatively, the clinician may switch between different types of fieldshapes by selecting a switch icon (not shown) or some other icon infield shape selection menu 200.

FIGS. 11A and 11B illustrate possible field shape groups 226 and 238that could be provided by field shape selection menus of any GUIsdescribed herein. In particular, field shape groups 226 and 238 are ofthe idealized neuron activation type to represent which tissue would beactivated from the electrical stimulation therapy. As shown in FIG. 11A,activated neurons are represented by field shape 228 which is anidealized oval, e.g., stripes, and the inhibited neurons are representedby field shape 230 which is a half-circle arc (e.g., with concave andconvex sides) to symbolize a shield of those neurons from beingactivated from field shape 228. The neuron activation field shape group226 may have shields present on one side of activation field shape 228.To further describe this shielding concept, the activation field shape228 may be equivalent to cathode 236 of lead 232 whereas field shape 230may be equivalent to anode 234 of lead 232. Field shape 230 may bereferred to as a shield, as the shield does indicate the shape of theactivation of neurons. In addition, providing the field shapes 228 and230 of field shape group 226 may eliminate the need to indicate thevector of the electrical current because the vector is inherent with theactivation and shield representations of field shape group 226.Alternately, a clinician may be allowed to select field shape groupsthat most closely represent the clinician's mental model of theoperation of the stimulation therapy.

FIG. 11B shows field shape group 238 which includes field shape 240surrounded by field shapes 242 and 244. Field shape 240 is the neuronactivation field shape while field shapes 242 and 244 are the inhibitionor shielding field shapes. Field shape group 238 may be equivalent tothe electrode combination of lead 246. Field shape 240 correlates tocathode 250 while field shapes 242 and 244 correlate to anodes 248 and252, respectively. The clinician may select field shape group 238 inorder to stimulate a desired tissue of patient 12 while preventingadjacent tissue from being activated during therapy. Inhibition ofcertain tissue may prevent the creation of adverse side effects that mayoccur from unshielded activation of tissue.

Since the shield, e.g., field shapes 230, 242, or 244, is used by theclinician to prevent activation from occurring at those locations, theshield may be similar to a keepout region of which the clinician prefersnot to activate those neurons. In particular, field shapes 230, 242, or244 may be intuitive to novice clinicians or clinicians that prefer toseparate actual physics of generating electrical stimulation from thephysiological programming process for efficacious therapy. Shapes offield shapes 230, 242, or 244 may change according to activation fieldshapes 228 and 240 near each shield field shape. In other examples, ashape different than the half-circle may be used to represent theshielding or inhibition concept to the clinician. For example, theshield may be shown as an open circle, a line, a triangle, or any othershape.

FIG. 12 describes GUI 254 and the usage of field shape selection menu258 in relation to stimulation region 260. As shown, GUI 254 includesfield shape selection menu 258, field shape manipulation tool menu 60,and a stimulation region 260 comprising side and depth regions 261 and268. In some embodiments, stimulation region 260 need not includestimulation depth region 268. Field shapes 270A and 270B (collectively“field shape group 270”) in field shape selection menu 254 areactivation functions, wherein field shape 270A is an inhibition shapeand field shape 270B is an activation shape. Field shapes 270A and 270Bmay be placed within stimulation field 260 and are usually are placedover a particular one of lead representations in side view region 261.As shown, field shape groups 278 and 280 have been placed within sideview region 261.

When the clinician drags field shapes from field shape selection menu258 to one of the leads, GUI 254 may support a “snap” ability thatcorrectly places the selected field shapes directly over one or morefull electrodes when the clinician positions the field shape closeenough to the actual center of the electrode or just the nearest fullelectrode of the lead. In additional examples, stimulator 14 may not becapable of centering a field shape away from the center of an electrode.In this case, stimulator 14 may snap the shape to the nearest fullelectrode. Hence, processor 22 (FIG. 2) may be configured to operatewith knowledge of the actual capabilities of the stimulator 14 for whichprogramming is performed. Snapping field shapes into place overparticular electrodes, for stimulators that are capable or incapable ofcentering a field shape away from the center of an electrode, may reducetime spent by the clinician in attempting to precisely place fieldshapes over a particular electrode.

In other examples, field shape groups 278 and 280 may not need to beplaced over a particular electrode. If stimulator 14 includes multiplecurrent or voltage sources, the stimulator may support placing fieldshape groups 278 and 280, or any other field shapes, anywhere withinstimulation region 260. Stimulator 14 may be capable of creatingactivation of tissue away from electrodes through the use of multipleelectrodes adjacent to the desired stimulation area. However, theclinician may not need to know how stimulator 14 will function in orderto reproduce the stimulation field defined by the placement of fieldshapes within stimulation region 260. In this manner, the clinician mayfocus on correct placement of the field shapes to treat certain tissueof patient 12.

GUI 254 also allows the clinician to manage field shape groups 278 and280. The clinician may be able to name field shape groups 278 and 280 orother field shapes, selectively activate or inactivate field shapes, oradd new field shapes to stimulation region 260. As an example, a fieldshape group 270 may be named to refer to an anatomical region of patient12 in which the group produces paresthesia or other therapeutic effects,e.g., such as leg, back, arm, or the like. In FIG. 12, the clinician hasnamed field shape group 278 as “Leg” and field shape group 280 as“Back.” Field shape group 278 has been snapped to full electrodes.However, field shape group 280 is located between full electrodesaccording to the desire of the clinician. In addition, GUI 254 andstimulator 14 may support simultaneous field shapes placed over eachother. Programmer 20 may generate stimulation parameter values, i.e.,programs, for each of field shape groups 278 and 280 and requirestimulator 14 to interleave the programs for each group in order toreproduce the therapy defined by the clinician. Field shape groups 278and 280 may also be characterized by attributes of their resultingstimulation. These field shapes categories may organize field shapesaccording to field shapes that provide ‘deep,’ ‘medial,’ or ‘lateral’field shapes. These field shapes may also be categorized according tolongitudinal or transverse field shapes.

As also shown in FIG. 12, GUI 254 may support tabbed programming. Tabbedprogramming refers to the method of organizing multiple groups of fieldshapes placed within stimulation region 260. The clinician may select atab, e.g., leg tab 262 or back tab 264, to allow manipulation of thecorresponding group of field shapes. For example, if the clinicianselects leg tab 262, field shape group 278 may be manipulated with iconsfrom the field shape manipulation tool menu 60 or added to using fieldshape group 270 or other field shapes from field shape selection menu258. Instead of tabbed programming, GUI 254 may include other icons orindications that allow the clinician to access the groups of fieldshapes within stimulation region 260.

FIGS. 13A-13C provides examples of specific electrode configurations forfield shapes that may be used by programmer 20. Each field shape isessentially a template that defines a particular set of stimulationparameter values to begin the programming process. Field shapes may bepreset to cover the most common electrode configurations used by theclinician or for a particular therapy. The clinician may add more fieldshapes to the library of programmer 20, or the clinician may request newfield shapes from a technician or manufacturer of the programmer. Thepreset electrode configurations correlate to field shapes used by GUI52, for example, may be designed to allow full use of actions in thefield shape manipulation tool menu for clinician customization. Lesscommon electrode configurations may be created by the clinician throughmanipulation of the field shapes, combination of field shapes, or anyother type of field shape functionality desired by the manufacturer orclinician.

As shown in FIG. 13A, longitudinal field shapes may include commonelectrode configurations that arise from electrodes located on the samelead. In this manner, the field shapes do not require electrodes from anadjacent lead in order to be implemented. As shown in FIG. 13A, leads282A-F illustrate example electrode configurations for field shapescreated by electrodes on one lead. Leads 282A and 282B include only oneanode and one cathode adjacent to each other, while lead 282C includesone cathode flanked by two anodes. Lead 282D illustrates an electrodeconfiguration with an anode and a cathode separated by an unusedelectrode, and leads 282E and 282F include just one anode and just onecathode, respectively.

However, transverse and three column field shapes may require one ormore electrodes from two or more leads implanted within patient 12,e.g., a cathode is located on one lead while an anode is located onanother lead. FIG. 13B provides lead pairs 284A and 284B. Transverseelectrode configurations may have an anode on lead 286A and a cathode onlead 286B. Alternatively, transverse electrode configurations may have acathode on lead 286C and an anode on lead 286D. In any case, electrodeconfiguration including two adjacent leads may be used to create certainfield shapes for the clinician.

FIG. 13C illustrates common electrode configurations for field shapesthat require the use of three leads and electrodes active on each of thethree leads. These field shapes may be less common in some therapieswhere fewer leads provide effective therapy. As shown in FIG. 13C,electrode configuration 288A includes a cathode on lead 290B with anodeson adjacent leads 290A and 290C. Electrode configuration 288B includes acathode on lead 290E with anodes on each of leads 290D, 290E, and 290Fto surround the cathode. It should be noted that any of these electrodeconfigurations may be presented as any of the field shape typesdescribed herein. For example, the field shapes associated with theelectrode configurations of FIGS. 13A-13C may illustrate currentdensity, an activation function, or neuron activation. Certain fieldshapes may be eliminated from use by programmer 20 depending on theconfiguration of leads 16 implanted within patient 12.

In the case of a single activation or inhibition field shape selected bythe clinician, programmer 20 may need to automatically place additionalactivation or inhibition field shapes within the stimulation region.When an opposing field shape is needed to be automatically placed byprogrammer 20, programmer 20 may maximize the effect of the field shapeplaced by the clinician. For example, the clinician may select and placean activation field shape to target a particular area of the stimulationregion. This placed field shape is essentially a unipolar electrode.Therefore, if stimulator 14 allows, programmer 20 would ideally set thehousing of stimulator 14 as an anode to provide low intensity inhibitionareas. Otherwise, programmer 20 may select one or more electrodes asanodes (inhibition field shapes) furthest from the desired activationfield shape location. Alternatively, a single inhibition field shapewould be automatically accompanied by one or more cathodes (activationfield shapes) closest to the inhibition field shape in order to maximizethe intensity of the inhibition.

FIGS. 14A-14D illustrate different representations of field shape groupsas templates to define a stimulation field and corresponding activationmodel. The examples of field shapes include a long bipole in FIG. 14A, aguarded cathode in FIG. 14B, a 3 lead full guard in FIG. 14C, and atransverse tripole in FIG. 14D. Each template is shown with the activeelectrodes of each lead, the activation model, and the idealizedrepresentation of the model. FIG. 14A provides electrode configuration292 that includes cathode 294A and anode 294B. Electrode configuration292 may correspond to activation field shape group 296 or modeledactivation model field shapes 300A and 300B (collectively “field shapegroup 300”) placed on spinal cord 298. Field shape group 296 may be theidealized representation that is provided to the clinician within thefield shape selection menu. In any case, the activation function formulais used to calculate the activation on the surface of the white matterof the spinal cord.

FIG. 14B shows electrode configuration 302 that includes cathode 304Bguarded by anodes 304A and 304C on the same lead. Field shape group 306includes an activation field shape and two inhibition field shapes thatflank the activation field shape according to electrode configuration302. Field shape group 306 illustrates an idealized activation fieldshape group which may also be shown by activation model field shapes310A, 310B, and 310C (collectively “field shape group 310”) provided onspinal cord 308. The idealized field shapes of field shape group 306 maybe shown using in color in some examples instead of striped or shadedfield shapes.

FIG. 14C illustrates an example of three lead full guards which utilizeselectrodes on all three leads implanted within patient 12. Specifically,electrode configuration 312 includes cathode 314A of the middle leadbeing surrounded by two anodes 314B of the same lead and anodes 314B ofthe leads on either side of cathode 314A. In this manner, the clinicianmay select idealized activation field shape group 316 to only activatethe tissue around the cathode while inhibiting the tissue on all sidesof the cathode. The activation model field shapes 320A, 320B, and 320Con spinal cord 318 provide an example of how the tissue will be affectedby electrode configuration 312.

Alternatively, FIG. 14D provides a transverse tripole example accordingto electrode configuration 322 which includes cathode 324A in the middlelead while electrodes of adjacent leads include anodes 324B. Theresulting activation of tissue using electrode configuration 322 may bea small area of activated tissue around the cathode as shown by theactivation on spinal cord 328. Activation model 330A is shown assurrounded by inhibition models 332B. Therefore, the clinician mayselect idealized field shape group 326 as and activation field shapewith two smaller inhibition field shapes to inhibit tissue on eitherside of the activated cathode. Any of the configurations shown in FIGS.14A-14D may be used anywhere along implanted leads or in combinationwith other configurations in order to treat patient 12.

FIGS. 15A-15D illustrate electrode configurations 392, 302, 312, and 322of FIGS. 14A-14D, respectively, and associated models of current density(e.g., as opposed to the associated activation functions illustrated inFIGS. 14A-14D). As shown in FIG. 15A, electrode configuration 292 isprovided to indicate some of the stimulation parameter values that mayresult in a current density model 340 of axial view 334. Current densitymodel 340 is shown within subarachnoid space 336 adjacent to spinal cord338. The axial view 334 is a cross-section that corresponds to themiddle of cathode 294A in FIG. 15A and FIGS. 15B-15D. Current densitymodel 340 indicates how the current density from electrode configuration292 will propagate through spinal cord 338 and subarachnoid space 336.Darker shading within current density model 340 indicates higher currentdensity than lighter shading.

FIG. 15B illustrates electrode combination 302 that includes anodes 304Aand 304C on either longitudinal side of cathode 304B. In this manner,the current density model 348 indicates that current propagates slightlyfurther from cathode 304B in the radial direction than cathode 294A ofelectrode configuration 292 that is flanked by only one anode 294B.Axial view 342 includes spinal cord 346 surrounded by subarachnoid space344.

FIG. 15C provides electrode configuration 312 that includes one cathode314A surrounded by anodes 314B above, below, and on either sides of thecathode. Axial view 350 includes a cross-section of spinal cord 354surrounded by subarachnoid space 352. Current density model 356 ismodeled to be spread out between all electrodes with a greater densityfurther from the cathode. The current density of current density model356 is shown as increased in surface area and depth in relation toeither current density models 340 or 348.

FIG. 15D shows electrode configuration 322 with cathode 324A surroundedby anodes 324B on adjacent leads. In comparison to electrodeconfiguration 312, the transverse configuration of electrode combination322 spreads the current density along the surface of spinal cord 362 andsubarachnoid space 362 without penetrating as deep into the tissue.While not shown in axial view 358, the current density generated fromelectrode configuration 322 may be reduced longitudinally when comparedto electrode configuration 312. These and other configurations may bemodeled and provided to the clinician as the stimulation depth region inGUI 52, for example, of programmer 20. Alternatively, axial views 334,342, 350, and 358 may even be a separate view alternative to the regularGUI that includes the stimulation region.

FIGS. 16A-16B show electrode configurations 392, 302, 312, and 322 ofFIGS. 14A-14D, respectively. However, FIGS. 16A-16D illustrate neuronactivation plots, or models, for each electrode configuration, insteadof current density (FIG. 15) or activation functions (FIG. 14). The areashaded in each neuron model depth view, e.g., shaded area, indicates theneurons that would be activated from stimulation with the associatedelectrode configuration. The axial views of the spinal cord shown are atthe location in the center of the cathode of the leads.

FIG. 16A illustrates electrode configuration 292 and an associatedneuron activation plot 370 in an axial or depth view 366. Neuronactivation plot 370 is shown within spinal cord 368. Axial view 366 is across-section that corresponds to the middle of cathode 294A in FIG. 16Aand FIGS. 16B-16D. Neuron activation plot 370 indicates which neurons ofspinal cord 368 are activated by the current from electrodeconfiguration 292. Neuron activation plots of FIGS. 16A-16D may begenerated using similar stimulation parameters such as pulse width,pulse rate, and current or voltage amplitude. Changes in any of theseparameters may change the neuron activation plot accordingly.

FIG. 16B illustrates electrode configuration 302 that includes anodes304A and 304C on either longitudinal side of cathode 304B. Correspondingneuron activation plot 376 indicates that neurons further into thecenter of spinal cord 374 are activated from cathode 304B. The presenceof nodes 304A and 304B create the deeper neuron activation thanelectrode configuration 292. Axial view 372 may show spinal cord 374 andneuron activation plot 376.

FIG. 16C illustrates electrode configuration 312 that includes onecathode 314A surrounded by anodes 314B above, below, and on both sidesof the cathode. Axial view 378 includes a cross-section of spinal cord380. Neuron activation plot 382 corresponding to electrode configuration312 is spread out between all electrodes with a greater degree of neuronactivation further from the cathode. The neuron activation illustratedby neuron activation plot 382 is increased in surface area and depth inrelation to either neuron activation plots 370 or 376.

FIG. 16D shows electrode configuration 322 with cathode 324A surroundedby anodes 324B on adjacent leads. In comparison to electrodeconfiguration 312, the transverse configuration of electrode combination322 reduces the activation of tissue along the sides of spinal cord 386while penetrating the neuron activation deeper within spinal cord 386.While not shown in axial view 384, the neuron activation generated fromelectrode configuration 322 may be reduced longitudinally when comparedto electrode configuration 312. These and other configurations may bemodeled and provided to the clinician as the stimulation depth region 61in GUI 52, for example, of programmer 20. Alternatively, axial views366, 372, 378, and 384 may be provided as an alternative to the standardstimulation region, e.g., 58, of the GUI's described herein.

FIGS. 17-29 are conceptual diagrams illustrating the modification ofstimulation shapes using the field shape manipulation tool menu 60 andother tools. FIG. 17 illustrates two actions that the clinician mayselect from the field shape manipulation tool menu of any of the GUIsshown herein. The clinician may split field shapes 394A, 394B, and 394Cwhich make up field shape group 392 shown with respect to lead 390.Splitting field shapes may move the stimulation field across a pluralityof electrodes in a plurality of steps, e.g., five steps as illustratedby FIG. 17, before two separate field shape groups 410 and 414 arecreated. Conversely, the clinician may merge two or more field shapes orgroups of field shapes to cover fewer electrodes. As shown in theexample of FIG. 17, the clinician has placed activation field shapegroup 392, including one activation field shape 394B surrounded by twoinhibition field shapes 394A and 394C, onto a representation of a lead390 with five electrodes. Only three electrodes are covered initially instep 1. Lead representation 390 is shown in each of the five steps asthe field shapes are changed according to the movement of activeelectrodes.

Once the clinician placed field shape group 392 over lead representation390, the clinician may select the split icon from the field shapemanipulation tool menu (not shown). Once the clinician selects thisoption, processor 22 splits field shape group 392 in step 2 by addinganodes on either side of the initial anodes for field shapes 394A and394C to create larger inhibition field shapes 398A and 398C on eitherside of activation field shape 398B. After step 2, the clinician mayagain select the split icon, or the field shapes may continue splittinguntil stopped by the clinician. To move to the third step, processor 22removes the middle anodes such that activation field shape 402B isseparated from the other inhibition field shapes 402A and 402C by onefull, non-activated, electrode of lead 390. On the fourth step,processor 22 adds cathodes on either side of activation field shape 402Bto create one large activation field shape 406B with three cathodes inbetween inhibition field shapes 406A and 406C. On the fifth and finalstep of splitting, processor 22 removes the center cathode from theelectrode configuration of lead 390 to create two separate field shapegroups 410 and 414. Field shape group 410 includes activation fieldshape 412B and inhibition field shape 412A, and field shape group 414includes activation field shape 416A and inhibition field shape 416B.The clinician may stop at any one of the steps to create a stimulationfield with the shown field shapes, depending on what is desired. Inother examples, current density or neuron activation field shapes may beshown during the splitting process, as determined by the clinician. Thisprocess may take place in separate splitting operations, or in a singleoperation that proceeds automatically in a continuous or discretefashion under the control of the clinician or other user.

In some examples, the steps may be used to automatically progresscompletely from step one to step five during real-time stimulationtherapy programming. In other words, the steps may be used so thatpatient 12 perceives few or no abrupt changes in therapy during thesplitting transition. Alternatively, each of steps 1 through 5 may besubdivided into multiple substeps or intermediate field shapes in orderto further reduce the perceptibility of the change in therapy. Thechanges between each step may be controlled using multiple currentsources for the stimulation parameters for each step or interleavingpulses for each stimulation parameters that define the two steps using asingle current source. The clinician may specify the number of steps,transition time period, or any other factor that adjusts how programmer20 controls changes to the electrical stimulation.

FIGS. 18A and 18B illustrate example control handles for field shapes offield shape groups 418A and 418B to allow manipulation of the fieldshapes. In the example of FIG. 18A, field shapes 420 and 422A areactivation/inhibition function field shapes connected in field shapegroup 418A. Similar control handles may be provided for other fieldshape types. Field shape group 418A include three control points 424,426, and 428, each operating as a control handle, which allow theclinician to manipulate each field shape 420 and 422A or both fieldshapes together. In this manner, the clinician may selectively adjustone or both field shapes 420 and 422A as desired. The clinician may usea pointing device of programmer 20 to select a particular control point(“handle”) to adjust the associated field shape, such as the orientationor position of field shapes 420 and 422A.

As shown, inhibition field shape 422A includes control point 428 thatallows positional adjustment, i.e., movement, of only inhibition fieldshape 422A. Activation control point 426 allows positional adjustment ofonly activation field shape 420. In addition, the two field shapestogether form a single field shape group 418A that also includes controlpoint 424 that adjusts the position of field shape group 418A as asingle object. In addition to three control points 424, 426, and 428,field shapes 420 and 422A may also have one or more control arrows 430that allow the clinician to change the size of the respective fieldshapes. The clinician may select control arrow 430 and move the controlarrow to change the size of field shape 422A, e.g., by stretching orshrinking field shape 422A in one dimension or simultaneously expandingor shrinking field shape 422A in equal proportions in two dimensions.The resulting stretching of inhibition field shape 422A with controlarrow 430 may create larger inhibition field shape 422B of field shapegroup 418B. Control points 424, 426, and 428 and arrow 430 may besimilar to repositioning and resizing tools provided in graphicaldrawing applications such as Microsoft Visio. A control arrow maycontrol a group of field shapes or a single field shape. In general, thecontrol arrow may be placed on an outer edge of the field shapes;however, the control arrow may be placed anywhere on the field shapes.In other examples, the control tools may include rotational controlpoints that permit rotation of a set of field shapes, e.g., from avertical orientation to a horizontal or angular (e.g., rotated 45degrees) orientation.

In some examples, the use of control points, control arrows, or othersuch adjustment options on field shapes may mean that separate actionsin a field shape manipulation tool menu may not be necessary formanipulation of the field shapes. In other words, each actionrepresented by an icon in the field shape manipulation tool menu may besubstituted by a tool located on each field shape, which can bemanipulated with a stylus, mouse, directional arrows, trackball or otherpointing device. These tools may be similar to control points 424, 426,and 428 and control arrow 430. In addition, the clinician may be able toselect how to manipulate the field shapes, either through the fieldshape manipulation tool menu or control points.

FIG. 19 is an example GUI 432 in which the clinician has selected moveicon 454 from field shape manipulation tool menu 440. GUI 432 is similarto GUI 52 (FIG. 4) but includes additional features. As shown in FIG.19, GUI 432 includes field shape selection menu 436, field shapemanipulation tool menu 440, and stimulation region 438 including sideview region 441 and depth view region 442. In addition, the user maycontrol the manipulation of field shapes within stimulation region 438with play slow icon 464, play fast icon 466, pause icon 468, and reverseicon 470.

Field shape group 472 is initially placed within stimulation region 438over lead side view 470A. Field shape group 472 may be created by theclinician dragging field shape group 444 from field shape selection menu436. The clinician uses field shape manipulation tool menu 440 to alterfield shape group 472 within stimulation region 438. The movement offield shape group 472 may be caused when the clinician selects move icon454 from field shape manipulation tool menu 440. The clinician may thenselect field shape group 472 and dragging it to the new location asindicated by field shape group 476. Arrow 474 indicates the direction inwhich field shape group 472 is moved within stimulation region 438 tothe new or target location the stimulation region. GUI 432 may show thenew location of field shape group 476 and original location of fieldshape group 472 together so that the clinician has an indication of themove action just completed. Arrow 474 may show the moved field shapecombination, or another technique such as transparency, animation, ornumbering may be used in place of the arrow. In some examples, GUI 432may prompt the clinician to confirm the movement of field shape group472 before field shape group 476 is completed.

The actual movement of field shape group 472 within stimulation region438 may be done without changing the stimulation therapy. In order tochange the stimulation therapy according to the new location of fieldshape group 472, the clinician may utilize implementation toolbar 443 asshown at the bottom of GUI 432. Implementation toolbar 443 may allow theclinician to control how and when the change is transferred tostimulator 14 for changing the stimulation delivered by the stimulator.Implementation toolbar 443 may include play slow icon 464, play fasticon 466, pause icon 468, and reverse icon 470, similar to a video oraudio playback system. Play slow icon 464 and play fast icon 466indicates that stimulation transitions from the starting field shapegroup 472 to the field shape group 476 gradually or quickly. Speedcontrol may be achieved by varying the number of steps, e.g., the numberchanges to electrode configuration and other stimulation parametervalues, between endpoints, e.g., initial and target field shapelocation/configuration, for the desired change in stimulation fields.Speed control may additionally or alternatively be achieved by changingthe size of those steps, or the rate at which steps are sent tostimulator 14 for execution. In other words, the clinician may havecontrol of how stimulator 14 shifts from the old therapy using fieldshape group 472 to the new therapy utilizing the new field shape group476. This control may only be necessary when the clinician is notproviding stimulation therapy according to the programming in real-time.In other embodiments, stimulation changes may take place in real-time,wherein parameter changes are sent to stimulator 14 as soon as fieldshape group 472 is modified.

FIGS. 20A and 20B provide example methods for moving field shape groupsin an iterative manner so that patient 12 does not feel an abrupt changein stimulation therapy when the field shape groups are moved. FIG. 20Ashows field shape group 484 over lead representation 482. Field shapegroup 484 includes field shapes 486A and 486B over two of the fiveelectrodes of lead representation 482. Arrow 488 indicates the directionin which the clinician has desired to move field shape group 484.

The steps from one to five of FIG. 20A show changing field shape group484 by iteratively adding and removing anodes and cathodes along thelead representation. In the second step, a cathode is added in thedirection of arrow 488 along lead representation 482 to create fieldshape 492A and field shape 492B before the original cathode is removedin step three to create field shape 496A and field shape 496B. In stepfour, an anode is added to lead representation 482 and the originalcathode location to create field shape 500A and field shape 500B beforethe original anode is removed in step five along lead representation 482from the electrode combination of step 498. The resulting field shapegroup 504 includes field shapes 506A and 506B moved down one electrodeposition of lead 482.

In this manner field shape group 484 may be shifted to the new positionof field shape group 504 without turning the therapy off and then onagain. Patient 12 may not perceive abrupt changes in therapy duringthese five steps. Alternatively, each of these five steps may besubdivided into one or more substeps in order to further reduce theperceptibility of the change to patient 12. Furthermore, althoughdescribed with reference to automatic steps in which the user controlsdirection and rate using the controls of implementation toolbar 443,other embodiments may involve the user manually and discretelycontrolling each step in either direction using implementation toolbarcontrols, such as arrows, or graphical forward and back buttons. Otherfield shape group types of more than two field shapes may move in asimilar manner such that only one anode or cathode is added or removedat any one time.

FIG. 20B shows field shape group 510 with spaced electrodes and apossible method in which to move field shapes 512A and 512B. In eithercase, the movement of field shapes 512A and 512B may employ multiplesteps to reduce the coarseness of field shape group 510 movement andassociated therapy changes. The movement of field shape group 510 mayoccur in fewer steps than illustrated in FIG. 20A because field shapes512A and 512B are separated along the electrodes of lead 508. Multipleanodes and cathodes may be added or removed to more quickly change thefield shape locations. In this manner the second step of FIG. 20Binvolves the addition of an anode and cathode in the direction of arrow514 to produce field shapes 518A and 518B along lead 508. Step threeinvolves removing the original anodes and cathodes to create field shapegroup 522 made up of field shapes 524A and 524B on lead 508.

Single source systems, i.e., in which a single source, such as pulsegenerator 38, delivers current or voltage stimulation, may shift fieldshapes coarsely because of needing to make the change in electrodeconfiguration with fewer steps. However, multiple source systems, i.e.,in which multiple sources deliver current or voltage simultaneously, maybe able to shift the field shapes, and corresponding electrodeconfigurations smoothly with a greater number of smaller steps betweenthe old and new field shape locations. The smoother transitions withmultiple sources may also utilize partial electrode activation to makethe movement of the field shapes as continuous as possible. Partialelectrode activation may refer to delivery of stimulation energy (e.g.,current or voltage) to both a starting electrode and an ending electrodeto effect a transition from one to the other over one or more steps. Forexample, to move a field shape from a first electrode to a secondelectrode, e.g., for rotation or other movement, the stimulationdelivered to the first electrode may be gradually decreased while thestimulation delivered to the second electrode is gradually increased,until the first electrode delivers no stimulation amplitude for thepertinent field shape and the second electrode delivers all of thestimulation amplitude for the field shape, at which time the transitionis complete. Alternatively, moving field shapes in this manner may notbe necessary when a clinician programs the therapy off-line.

FIG. 21 illustrates an example of GUI 432 with field shape group 526being rotated within the stimulation region 438. In the example of FIG.21, the clinician has selected rotate icon 456 from field shapemanipulation tool menu 440 and selected the desired field shape group526 to be rotated from lead side view 478A. Specifically, the clinicianhas indicated with arrow 530 to move field shape group 526 about theactivation field shape (illustrated as striped in FIG. 21). Theclinician has indicated that the new location of the inhibition fieldshape of field shape group 526 is rotated to lead side view 528. Hence,the activation field shape of field shape group 526 and 528 is theanchor for the rotation of the inhibition field shape from an electrodeon lead side view 470A to an electrode on lead side view 470B. Thepending rotation of field shape group 526 to field shape group 528 isrepresented by arrow 530 showing the rotational direction of theoriginal field shape group. Other representations of field shape groups526 and 528 may include transparencies, opaque field shapes, animations,or other representations that indicate a transition between an originaland new field shape group.

Once the clinician has selected to rotate field shape group 526, theactual change to stimulation therapy in real-time programming situationsmay wait until the clinician confirms the change to the stimulationfield in stimulation region 438. The clinician may also use animplementation toolbar 443 to indicate how to change stimulationtherapy. In some embodiments, as discussed above, the implementationtoolbar may include controls that allow the clinician to discretelycontrol each of a plurality of steps from the initial field shape orgroup 525 to the target field shape or group 528. In other examples, thechange of field shape group 526 to field shape group 528, and theresulting change in delivered stimulation therapy, may occurinstantaneously with shape movement and continue until the clinicianstops rotating the field shape group.

FIGS. 22A and 22B are examples of how programmer 20 may direct therotation of a field shape group during real-time programming withpatient 12. FIG. 22A illustrates lead representations 532A and 532B withfield shape group 534 located on lead representation 532A. In threesteps, the clinician rotates field shape group 534, specificallyinhibition field shape 536A, in the direction of arrow 535 around theanchor position of activation field shape 536B. In the first step theclinician places field shape group 534 onto lead representation 532A,wherein the field shape group includes inhibition field shape 536A andactivation field shape 536B. There is no field shape over leadrepresentation 532B, but the clinician desires to rotate field shapegroup 534 in the direction of arrow 535. In the second step, an anode isadded on the electrode of adjacent lead representation 532B to leadrepresentation 532A. The resulting intermediate field shape groupincludes field shape 540A across both lead representations 532A and 532Band field shape 540B still on lead representation 532A. In the thirdstep, the original anode is removed to result in field shape group 544spreading across lead representations 532A and 532B in a diagonal fieldshape group. Field shape group 544 includes inhibition field shape 546Aand activation field shape 546B. In some examples, the clinician maycontinue to rotate field shape group 544 around the anchored cathode offield shape 546B shown as the activation field shape.

FIG. 22B illustrates an initial field shape group 550 within three leadrepresentations 548A, 548B, and 548C (collectively “leads 548”) as thefirst step. Field shape group 550 includes a cathode for field shape552B surrounded by two anodes of field shapes 552A and 552C. Field shapegroup 550 is shown as activation function field shapes, so field shape552B is an activation field shape and field shapes 552A and 552C areinhibition field shapes. Two-headed arrow 535 indicates the direction inwhich inhibition field shapes 552A and 552B are rotated about activationfield shape 552B towards leads 548C and 548A, respectively. The secondstep of the rotation of field shape group 550 includes adding anodes tothe adjacent electrodes on adjacent lead representations 548A and 548Cin the direction of arrow 535 which in turn creates larger inhibitionfield shapes 556A and 556C over multiple lead representations. The thirdstep includes removing the original anodes on lead representation 548Bsuch that the only inhibition field shapes are inhibition field shapes562A and 562C on lead representations 548A and 548C. Activation fieldshape 562B remains in its original location of the middle of leadrepresentation 548B to create field shape group 560. Similar to the topimage, the clinician may be able to continue rotation of field shapegroup 560 around the anchored cathode that creates field shape 562B. Inthis case of FIG. 22B, the centroid of field shape groups 550 and 560are used as the anchor point when rotating the field shape groups. Inother field shape groups, the cathode may not be located at the centerof the field shape group or an anode may be used as the anchor pointwhen rotating the field shape group.

As indicated previously with the manipulation of field shapes, therotation of field shape groups in single current source stimulator 14may be coarse. However, a multiple current source stimulator 14 may becapable of creating partial electrodes to create a more seamless orcontinuous movement of the field shape group.

FIG. 23 is an example of manipulating field shapes and field shapegroups in such a manner as to grow or shrink the shapes in size,illustrated with respect to a GUI 564. GUI 564 includes field shapeselection menu 568, field shape manipulation tool menu 572, and astimulation region 570 including side and depth view regions 571 and574. In addition, GUI 564 includes size input 604, current amplitudeinput 606, and pulse width input 608. The clinician changes the size ofa field shape or field shape group by selecting a desired field shapeand selecting either grow icon 592 or shrink icon 594 of field shapemanipulation tool menu 572. The dotted lines indicate the selected fieldshape group, such as field shape groups 598, 600, or 602. GUI 564illustrates example bigger shapes, such as field shape group 598,resulting from growing the original field shape group selected fromfield shape selection menu 572 to smaller shapes, such as field shapegroup 602, resulting from shrinking the selected field shape group.

The clinician may change the size of any field shape or field shapegroup through a variety of control mechanisms, such as size input 604,current amplitude input 606, and pulse width input 608. The clinicianmay first add the field shape group from field shape selection menu 568,and adjust the size of the selected field shape as desired. Size input604 may allow the clinician to adjust the size of each selected fieldshape group as a percentage of the original field shape group. Forexample, original sized field shape group 598 may be shrunk 75% to fieldshape group 600. Size input 604 changes may correspond to voltageamplitude or current amplitude changes, depending upon desires of theclinician or the configuration of system 10. Current amplitude input 606allows the clinician to adjust the current amplitude of the field shapegroup, and pulse width input 608 determines the pulse width of theelectrical pulses delivered to patient 12.

In addition to the inputs shown in GUI 564, other input mechanisms maybe used in alternative embodiments. For example, the clinician mayprovide input via text entry boxes, dials, sliders, up/down arrows,drop-down menus or the like. In other embodiments, the clinician maychange the size of a field shape or field shape group by grabbing anouter edge of the field shape and drag the edge out to grow the fieldshapes or in to shrink the field shape. The clinician may initiallyconfigure GUI 564 to include any input mechanism necessary toeffectively program stimulation therapy.

As indicated, the grow icon 592 or shrink icon 594 may be used for anyparticular field shape, even if the field shape is within a field shapegroup, or a complete field shape group. Further, any of the field shapemanipulation mechanisms of GUI 564 may be used within depth view region574 over axial views 596A and 596B of two leads 16. A change to a fieldshape or field shape group within side view region 571 or depth region574 will display a respective change in the other region withinstimulation region 570. In this manner the clinician may be able toquickly view the field shape with respect to the respective lead. Inaddition, GUI 564 may include a slider or other adjustment mechanism topan down the length of lead 596A and lead 596B. A corresponding slidermay be present within stimulation region 570 as a marker to the axiallocation of depth region 574.

FIG. 24 illustrates an example how field shapes grow or shrink at therequest of the clinician. Step one shows field shapes 614A, 614B and614C as field shape group 612. Field shape group 612 is shown over leadr 610A instead of lead representation 610B. Field shape group 612 may beinitially selected by the clinician from field shape manipulation toolmenu 572 of GUI 564, for example. Field shape group 612 shows activationand inhibition created by stimulation from the electrodes of the leadrepresented by 610A. Specifically, field shapes 614A and 614C areinhibition field shapes and field shape 614B is an activation fieldshape.

In one example, field shapes 614B may have a size defined by a currentof 10 milliamps (mA) while both inhibition field shapes 614A and 614Care created with 5 mA of current amplitude. In step two, the clinicianhas decided to shrink field shape 614C by changing the current amplitudeof field shape 620C to 2 mA of current. In addition, the clinician hasincreased the field shape 614A by changing the current amplitude offield shape 620A to 8 mA of current and field shape 620B has not changedin size from field shape 614B. This change of inhibition field shapes620A and 620C in step two may alter the effect of stimulation therapy topatient 12. In some examples the changes between field shape groups 612and 618 may occur in several discrete steps or a substantiallycontinuous manner to reduce any perceived transition effect to patient12 during real-time programming and stimulation.

A change in a field shape size, such as that between field shape 614Aand 620A, may correspond to any one of voltage amplitude, currentamplitude, pulse width, power output, or iterative combination of theseparameters. As shown between field shape groups 612 and 618 of FIG. 24,shrinking of field shape 614C to 620C within field shape group 618 maycause relative changes to field shape 620A in order to maintaininhibition or activation currents within field shape group 618. This mayoccur in order for the current to be balanced between the sources andsinks (activation areas and inhibition areas) of the stimulationtherapy. However, the clinician may also increase or decrease otherfield shapes, such as activation field shape 620B in order to balancecurrent within field shape group 618. In alternative embodiments, theclinician or system 10 may add or subtract other field shapes whenneeded to address any current issues without significantly altering thestimulation therapy of patient 12.

FIG. 25 provides an example illustrating how the clinician may stretchfield shape 624 within stimulation region 438 with reference to GUI 432.To adjust a field shape within field shape group 622, the clinician mayfirst select stretch icon 458 within manipulation tool menu 440 and thenselect the field shape or field shape combination to be stretched. Asshown in FIG. 25, the clinician has selected the activation field shapewithin field shape group 622. The clinician may grab an outer edge ofthe activation field shape and drag the side of the activation fieldshape until the field shape has been stretched to the satisfaction ofthe clinician or the limits possible of system 10. Arrow 624 indicatesthe direction in which the clinician has stretched the activation fieldshape. Arrow 624 may remain over the activation field shape to indicatethat the stretch action is pending approval from the clinician. Insteadof arrow 624, other pending indications may include animations, dottedlines, flag icons, transparencies, or any other representation that astretch action has been performed to field shape group 622 withinstimulation region 438. In other examples, the clinician may select tostretch the entire field shape group or a different field shape.

When delivering therapy to patient 12 in real-time, stretching theactivation field shape may occur without immediately modifyingstimulation during the stretching period. In order to implement thestretch change into the stimulation therapy, the clinician may utilizeimplementation toolbar 443. Implementation toolbar 443 may allow theclinician to control how and when the change is transferred tostimulator 14 for delivery to patient 12.

Implementation toolbar 443 includes play slow icon 464, play fast icon466, pause icon 468, and reverse icon 470, similar to a video or audioplayback system. Play slow icon 464 and play fast icon 466 indicate howstimulator 14 is to change therapy to the stretched field shape group622 within stimulation region 438. In other words, the clinician mayhave control of how stimulator 14 shifts from the old therapy using theoriginal field shape group to the new therapy utilizing the newstretched field shape group. This control may only be necessary when theclinician is providing stimulation therapy according to the programmingin real-time. The clinician may pause the change in stimulation byselecting pause icon 468 or reverse the change back to the originalstimulation by selecting reverse icon 470. Furthermore, in otherimplementation toolbar embodiments, as described above, a clinician maydiscretely control each of a plurality of steps from the original fieldshape to the stretched field shape using, for example, arrow buttonsprovided by the GUI.

FIGS. 26A and 26B provide example methods of stretching one or morefield shapes as described in FIG. 25 above. The steps of stretching thefield shapes may require the use of multiple current sources withinstimulator 14 in order to supply differing electrical parameters tomultiple electrodes that simulate partial electrodes. As shown in FIG.26A, field shape group 628 includes field shape 630A and 630B. Step oneillustrates arrow 632 that indicates the direction in which theclinician desires to stretch activation field shape 630B over leadrepresentation 626. Field shape 630A is not stretched in the example ofFIG. 26A.

In order to stretch activation field shape 630B in the direction of thearrow 632, stimulator 14 uses a partial electrode to slightly stretchthe geometry of field shape 630B in the direction of arrow 632. Step twoshows the initial field shapes 636A and 636B, each centered over theirrespective electrode. In step three, field shape 640A remains unchanged,but field shape 640B is stretched away from field shape 640A through theuse of a partial electrode on the adjacent electrode. Step fourindicates that field shape 646B is completely stretched over twoelectrodes, including another cathode in the direction of arrow 632,while field shape 646A remains unchanged. Field shape 646A and 646Bcreate the new field shape group 644 that the clinician may used todeliver therapy. In other examples, the clinician may stretch activationfield shape 646B over more than two full electrodes.

FIG. 26B shows the entire field shape group 650 about to be stretchedover four electrodes of lead representation 648. According to theinstructions of the clinician, field shape 652A is stretched in thedirection of arrow 651A. In addition, field shape 652B is stretched inthe direction of arrow 651B. Arrows 651A and 651B are representations ofthe direction that both inhibition field shape 652A and activation fieldshape 652B are to be stretched by stimulator 14.

Step two shows each of field shapes 656A and 656B over only oneelectrode of lead representation 648. In step three, both field shapes660A and 660B are stretched incrementally in opposite directions byusing partial electrodes adjacent to the original electrodes for fieldshapes 656A and 656B. In step four, both field shapes 666A and 666B arecompletely stretched over two electrodes of lead representation 648.Field shapes 666A and 666B create the new field shape group 664 thatdefines stimulation therapy to patient 12. In some embodiments, theclinician may be able to stretch one field shape before stretching theother field shape. Alternatively, field shapes 656A and 656B may bestretched in an alternating and iterative manner such that patient 12may generally feel a smooth change in stimulation.

In examples of stimulator 14 that only include a single current source,stretching field shapes may not be accomplished with partial electrodestretching. In this case, simulator 14 may need to coarsely stretch thefield shape by adding the appropriate anode or cathode to the next fullelectrode on the lead. While this method may cause patient 12 to noticeabrupt changes in stimulation therapy, stimulator 14 may be able tominimize the noticeable change. For example, stimulator 14 may slowlyramp up the current or voltage amplitude of the additional fullelectrode until the full amplitude is achieved.

FIGS. 27A and 27B illustrate example leads and electrode configurationsand corresponding axial views of stimulation depth on programmer 20 toallow the clinician to identify how stimulation therapy affects patient12 tissue. Specifically, the stimulation may be viewed within the spinalcord as modeled by programmer 20. In addition to allowing the clinicianto adjust field shapes within the a longitudinal view of the stimulationregion, the clinician may be able to view the depth of neuron activationdirectly in the axial view. As shown in FIG. 27A, electrodeconfiguration 668 includes one cathode 670A and one anode 670B.Electrode configuration 668 results in neuron activation 676 shown inaxial view 672. Neuron activation 676 is shown within spinal cord 674.Neuron activation 676 shows the current stimulation therapy as a shallowand spread out region in spinal cord 674. The clinician may select anddrag neuron activation 676 towards the center of spinal cord 674 in thedirection of arrow 678.

FIG. 27B illustrates changes to stimulation therapy with altered neuronactivation 688 from neuron activation 676 in FIG. 27A. By draggingneuron activation 676 in the direction arrow 678, programmer 20generated a new electrode configuration 680 in order to accommodate thedesired changes to therapy. Electrode configuration 680 includes acenter cathode 682B with anodes 682A on either side of the cathode tocreate stimulation reaching a deeper area within spinal cord 686. Neuronactivation 688 is shown in axial view 684. Processor 22 mayautomatically make the change to electrode configuration 680 in order todrive stimulation deeper into spinal cord of patient 12. Processor 22may accomplish these changes to therapy by selecting a pre-computed orpredefined field shape that most closely accomplishes clinician's goalby calculating the parameters in real time that would most closely matchthe desired field shape. Accordingly, axial view 684 indicates withneuron activation 688 that stimulation is deeper and less spread outalong the surface of spinal cord 686. The change in stimulation andassociated electrode configuration 680 of cathodes and anodes may bemade in an iterative manner to minimize the impact of the change instimulation on patient 12. In other cases, programmer 20 may change toelectrode configuration 680 in one step from electrode configuration668. The depth change shown in FIG. 27B may be similar to a grow orshrink action discussed above within the stimulation region of a GUI.

FIGS. 27A and 27B illustrate that the change from electrodeconfiguration 668 to electrode configuration 680 alters the currentdensity between anodes and cathodes to essentially focus the current toa particular area of spinal cord 686. However, the clinician may insteadchange the depth of the stimulation through modifying any one or more ofcurrent amplitude, voltage amplitude, pulse width, pulse rate, or anyother stimulation parameter. In addition, a combination of electrodeconfiguration changes and parameter changes may be used to adjust thedepth of the stimulation therapy.

FIG. 28 is an example screen shot of GUI 690 that allows the clinicianto use one or more field shapes to program stimulation therapy. GUI 690includes three zones, e.g., zones 692, 694 and 696, for programming.These zones may be provided on programmer 20 in one, two, three, or morescreens. First zone 692 allows the clinician to select a one of fieldshapes 700A, 700B, 700C or 700D (collectively “field shapes 700”). Theclinician uses selection box 698 to highlight the one of field shapes700 to use in defining the stimulation therapy. Field shape 700A is asingle field shape, field shape 700B is an elongated field shape thatuses multiple electrodes, field shape 700C is a tripole field shapegroup, and field shape 700D is a bipole field shape group. Field shapes700 may be of any type described herein, such as a current density fieldshape, an activation function field shape, or a neuron activation fieldshape. The adjust orientation knob 702 may be provided to allow theclinician to rotate the selected one of field shapes 700 as desired tobe placed within stimulation region 703 of second zone 694.

Second zone 694 of GUI 690 allows the clinician to place the selectedfield shape 706 within stimulation region 703. Stimulation region 703includes a general representation of spinal cord 704 of patient 12 thatmay or may not exactly match the anatomy of patient 12. As shown, theclinician has placed field shape 706 over spinal cord 703 near the T8vertebra. The clinician may select any of arrows 708, 710, 712 or 714 tomove field shape 706 as desired within stimulation field 703, e.g.,left, right, up, down. The clinician may also place more than one fieldshape or field shape group within stimulation field 703 to the extentthat stimulator 14 supports the stimulation.

The clinician may also use amplitude knob 718 to adjust the voltageamplitude. Adjusting amplitude knob 718 may accordingly adjust the sizeof field shape 706 within stimulation region 703. When the amplitude offield shape 706 is adjusted, amplitude indicator 716 may changerespectively. In the example of FIG. 28, the voltage amplitude beingused for field shape 706 is 2.25 volts. In other examples, amplitudeknob 718 and corresponding amplitude indicator 716 may be used to adjustcurrent amplitude instead of voltage amplitude. The amplitude adjustedin second zone 694 may depend upon the configuration of stimulator 14and/or the desires of the clinician. While stimulation region 703 onlyprovides a side view of spinal cord 704, other examples of GUI 690 mayinclude a depth view that shows the relation of field shape 706 tospinal cord 704.

Third zone 696 of GUI 690 allows the clinician to make fine adjustmentsto the shape of field shape 706 before or during application of thetherapy to patient 12. Example adjustments may include pulse width knob720 and pulse frequency knob 724. Adjustment of one of the knobs 720 or724 in third zone 696 may also result in a change the shape of fieldshape 706 displayed in stimulation region 706. Pulse width indicator 722and pulse frequency indicator 726 are also provided to show thenumerical stimulation parameter that currently defines field shape 706.Third zone 696 may also include other adjustments that the clinician mayutilize in order to create the desired therapy from field shapes placedwithin stimulation region 703. While some adjustments to stimulationparameters are shown as knobs, the adjustments may be accomplished usingsliders, up and down arrows, text fields, plus/minus buttons, joysticks,scroll wheels, or any other input media.

FIG. 29 is another example of a screen shot of GUI 728 that allows theclinician to program stimulation therapy. GUI 728 of FIG. 29 issubstantially similar to GUI 690 of FIG. 28. However, GUI 728 providesan exact representation of patient 12 anatomy with the implanted leads(e.g., leads 16). GUI 728 includes first zone 730, second zone 732 andthird zone 734. Field shapes 738A, 738B, 738C and 738D are provided tothe clinician and may be selected via selection box 736. The clinicianmay change the orientation of the field shape via adjust orientationknob 740 and precisely position field shape 744, or other field shapes,with arrows 746, 748, 750 and 752. Second zone 732 also allows theclinician to adjust the voltage or current amplitude via amplitudeadjustment knob 756 and amplitude indicator 754. Third zone 734 providespulse width knob 758, pulse width indicator 760, pulse frequency knob762, and pulse frequency indicator 764 in order for the clinician toadjust the stimulation parameters of field shape 744 and any other fieldshapes within stimulation field 743.

Image 742 that is used as background for stimulation region 743 may betaken post-surgery from patient 12 and mapped to the coordinate systemof programmer 20 to ensure correct placement of the field shapes withinstimulation region 742. In this manner, the clinician may directlyidentify anatomical positions of the spinal cord and associatedimplanted electrodes. As shown, the clinician has selected field shape744 and positioned field shape 744 over the second electrode of theright lead. Image 742 may be generated from fluoroscopy, but otherimages may be provided that are generated from x-ray, MRI, CT, PET, orany other imaging modality. In other examples, image 742 of patient 12anatomy may be provided and the clinician may manually indicate thelocation of each lead based upon surgical implantation results.

Field shapes as described herein are discussed as related to twodimensional programming using ring electrodes, but these methods ofprogramming electrical stimulation may also be used withinthree-dimensional (3D) programming application with ring electrodes orwith multiple electrodes arranged around the circumference of the lead,e.g., complex electrode array geometries. 3D programming may be usefulin SCS application and, more specifically, within DBS applications wheretarget tissues may be at a particular location around the circumferenceof each lead. By stimulating only the target tissues, the stimulationtherapy may avoid stimulation of additional tissues that may causeadverse effects in patient 12. The clinician may focus on the activationof tissue by using field shapes within 3D programming environments.Otherwise, the clinician may spend time trying to identify individualstimulation parameters that may cause certain activation or inhibitionof tissue.

Many embodiments of the disclosure have been described. Variousmodifications may be made without departing from the scope of theclaims. These and other embodiments are within the scope of thefollowing claims.

1. A method comprising: presenting on a display at least one view of arepresentation of a stimulation region; presenting on the display atleast one field shape group within a field shape selection menu;receiving selection input from a user selecting the at least one fieldshape group from the field shape selection menu; receiving placementinput from the user placing the at least one field shape group at aposition within the representation of the stimulation region; andgenerating electrical stimulation parameters based upon the field shapegroup and the position within the representation of the stimulationregion.
 2. The method of claim 1, wherein the field shape group displaysat least one of an activation function, a predicted neuron activation,or a current density.
 3. The method of claim 2, wherein the field shapegroup displaying the activation function comprises at least oneactivation field shape that indicates activation of tissue activity by acathode and at least one inhibition field shape that indicatesinhibition of tissue activity by an anode.
 4. The method of claim 1,further comprising snapping the field shape group to an electrodeclosest to the placement within the stimulation region.
 5. The method ofclaim 1, further comprising: presenting on the display at least onemanipulation icon within a manipulation tool menu; and receiving fromthe user a manipulation input via the at least one manipulation iconthat manipulates the selected at least one field shape within therepresentation of the stimulation region.
 6. The method of claim 1,further comprising presenting on the display within the representationof the stimulation region at least one of a representation of animplantable lead, a representation of one or more electrodes, or arepresentation of patient anatomy that corresponds to the stimulationregion.
 7. The method of claim 6, wherein the representation of anatomycomprises at least one of a somatotopic map, a tissue image, or ananatomical atlas.
 8. The method of claim 7, wherein the tissue image isrepresentative of the patient and generated via at least one offluoroscopy, magnetic resonance imaging, X-ray, computed tomography, orpositron emission tomography.
 9. The method of claim 7, wherein theanatomical atlas is a general representation of human anatomy.
 10. Themethod of claim 1, further comprising: restricting at least one unusableelectrode from a set of electrodes implanted within a patient to deliverstimulation therapy according to the generated electrical stimulationparameters; and blocking the at least one field shape group from an areaof the representation of the stimulation region associated with the atleast one unusable electrode.
 11. The method of claim 1, wherein therepresentation of the stimulation region illustrates a side view of thestimulation region.
 12. The method of claim 1, wherein the stimulationregion illustrates a stimulation depth region, wherein the stimulationdepth region illustrates the penetration of the at least one field shapegroup into tissue.
 13. A programmer comprising: a display; a processorthat presents on the display at least one view of a representation of astimulation region and at least one field shape group within a fieldshape selection menu; and a user interface that receives selection inputselecting the at least one field shape group from the field shapeselection menu and placement input placing the at least one field shapegroup at a position within the stimulation region, wherein the processorgenerates electrical stimulation parameters based upon the field shapegroup and the position within the representation of the stimulationregion.
 14. The programmer of claim 13, further comprising a memory thatstores field shape information that the processor uses to display the atleast one field shape group as an activation function, a predictedneuron activation, or a current density.
 15. The programmer of claim 13,wherein the processor snaps the at least one field shape group to anelectrode closest to the placement within the representation of thestimulation region.
 16. The programmer of claim 13, wherein theprocessor presents on the display at least one manipulation icon withina manipulation tool menu, and the user interface receives a manipulationinput via the at least one manipulation icon that manipulates the atleast one field shape selected within the representation of thestimulation region.
 17. The programmer of claim 13, wherein theprocessor presents on the display within the representation of thestimulation region at least one of a representation of an implantablelead, a representation of one or more electrodes, or a representation ofpatient anatomy that corresponds to the representation of thestimulation region.
 18. The programmer of claim 13, wherein theprocessor: restricts at least one unusable electrode from a set ofelectrodes implanted within a patient to deliver stimulation therapyaccording to the generated electrical stimulation parameters; and blocksthe at least one field shape group from an area of the representation ofthe stimulation region associated with the at least one unusableelectrode.
 19. The programmer of claim 13, wherein the user interfacecomprises the display.
 20. A computer readable medium comprisinginstructions that cause a processor to: present on a display at leastone view of a representation of a stimulation region; present on thedisplay at least one field shape group within a field shape selectionmenu; receive selection input selecting the at least one field shapegroup from the field shape selection menu; receive placement inputplacing the at least one field shape group at a position within thestimulation region; and generate electrical stimulation parameters basedupon the field shape group and the position within the representation ofthe stimulation region.
 21. The computer readable medium of claim 20,further comprising instructions that cause the processor to snap thefield shape group to an electrode closest to the placement within therepresentation of the stimulation region.
 22. The computer readablemedium of claim 20, further comprising instructions that cause theprocessor to presents on the display at least one manipulation iconwithin a manipulation tool menu, receive a manipulation input from theat least one manipulation icon within a manipulation tool menu thatmanipulates the at least one field shape selected within therepresentation of the stimulation region.
 23. The computer readablemedium of claim 20, further comprising instructions that cause theprocessor to present on the display within the representation of thestimulation region at least one of a representation of an implantablelead, a representation of one or more electrodes, or a representation ofpatient anatomy that corresponds to the stimulation region.
 24. Thecomputer readable medium of claim 20, further comprising instructionsthat cause the processor to: restrict at least one unusable electrodefrom a set of electrodes implanted within a patient to deliverstimulation therapy according to the generated electrical stimulationparameters; and block the at least one field shape group from an area ofthe representation of the stimulation region associated with the atleast one unusable electrode.
 25. The computer readable medium of claim20, wherein the field shape group displays at least one of an activationfunction, a predicted neuron activation, or a current density.